|Directed by||K. Madhu|
|Written by||S. N. Swamy|
|Produced by||K. Madhu|
|Starring|| Mammootty |
|Edited by||P. C. Mohanan|
|Budget||₹ 3 crore|
|Box office||₹ 8 crore|
Nerariyan CBI (transl. To know the truth CBI) is a 2005 Indian Malayalam-language mystery film directed and produced by K. Madhu and written by S. N. Swamy. The fourth installment in the franchise of CBI investigative thrillers, Mammootty reprised the role of Sethurama Iyer, a Central Bureau of Investigation officer, with Mukesh and Jagathy Sreekumar reprising their roles as the associate officers Chacko and Vikram respectively and the background score composed by Shyam. 
Like its prequels, Oru CBI Diary Kurippu (1988), Jagratha (1989) and Sethurama Iyer CBI (2004), Nerariyan CBI was also set as a murder mystery behind a lady, who found dead at a haunted mansion in suspicious condition.   
There was a murder in a house. The victim is Mythili. The dead body was seen by Lakshmiyamma first. It was seen that Mythili and her friends along with Anitha came just a day before the murder. And it was also widely said that a room in that bungalow is haunted. Sai, Anitha's fiancé, and a young police officer start to investigate the case but he also starts to believe that the room is haunted because of an incident that happened to him. Soon the case goes to the CBI. It was handled by Sethurama Iyer. Soon he investigates the case and finds out that the room is not haunted and it was a murder and that a few family members of that mansion were involved in the murder of Mythili.
The success of the previous film Sethurama Iyer CBI prompted the writer S. N. Swamy and director K. Madhu to join hands again for a one more installment in the series of CBI investigative thrillers. S. N. Swamy completed the screenplay in a time spanning one year. As the plot contained some supernatural themes as well, Swami had to conduct enough research over it. Director K. Madhu, who himself produced Sethurama Iyer CBI , decided to finance Nerariyan CBI too under his banner Krishna Kripa Productions. Madhu, who has collaborated with S. N. Swamy more than 10 films at the time, said, "What thrills us is that teenagers who saw 'CBI Diary Kurippu' are going to see 'Nerariyan' with their kids."
Shyam, who has composed the popular background score for the former films, was again hired for composing the score for the new film, which also lacks songs in its soundtrack. Associate director I. Sasi and production controller Aroma Mohan have remained in the crew from the former team. Saloo George, who was the associate of first two parts of series' cinematographer Vipin Das and has done cinematography in Sethurama Iyer CBI, was signed in to lead the direction of photography in Nerariyan CBI as well. Principal photography began after a discussion on whole screenplay was conducted, that was usual in former films too. Apart from Mammootty, Mukesh and Jagathi Sreekumar who comprised team of CBI investigators, Nedumudi Venu, Thilakan, Samvrutha Sunil, Gopika, Suja Karthika and Jishnu were added to the cast to play other prominent roles in the film. During the on-location filming "the trick of keeping the suspense alive till the end of the film" was difficult, according to Mukesh. 
A critic from Sify assessed the film as "good'" and lauded S.N.Swamy for "making something spectacular out of ordinary material", the "mood enhancing" background score by Shyam, and the "commendable" cinematography of Salu George, noting that "The highlight of the film is Mammootty as the suave and intelligent Sethurama Iyer who looks dashing and debonair. Another interesting highlight is the war of words between Iyer and Kapra (Thilakan), a local sorcerer which ignites the screen." The reviewer, however, criticised K. Madhu's "old school of film making" style and "irritating" frequent in-film ads. The review concludes by saying "On the whole, our two thumbs go up for the return of Sethurama Iyer. Can't wait for CBI-5!"   
Sethurama Iyer CBI is a 2004 Malayalam-language mystery crime film directed by K Madhu.The movie is written by S. N. Swami, and The movie stars Mammootty in titular role. Actors Mukesh and Jagathy Sreekumar played important supporting roles. Shyam composed the background score for the film.
Mayilattam is a 2004 Malayalam-language action comedy film directed by V. M. Vinu. It stars Jayaram in a dual roles along with Rambha, Indraja, and Jagathy Sreekumar in the pivotal roles. The film was a commercial success at the box office. It was an Onam release of 2004.
Senior Superintendent Sethurama Iyer CBI is a fictional character, and the main protagonist of the CBI series of investigative thriller films in Malayalam directed by K. Madhu. The character was played by Mammootty in five films so far.
Samuel Joseph, better known as Shyam, is a music composer who works in Malayalam cinema.
Oru CBI Diary Kurippu is a 1988 Indian Malayalam-language mystery thriller film directed by K. Madhu, written by S. N. Swamy, and starring Mammootty, Suresh Gopi, Jagathy Sreekumar, Mukesh, and Sukumaran. The lead character, CBI officer Sethurama Iyer is inspired by a police officer named Radha Vinod Raju, Jammu and Kashmir cadre IPS Officer who in 2009 was appointed as the first chief of India's National Investigation Agency. It was the highest grossing Malayalam film at that time. Considered one of the best crime thrillers in Malayalam, it eventually developed a cult following. This is the first instalment in the CBI film series featuring Mammootty as Sethurama Iyer.
Jagratha: CBI Diary - Part 2 (transl. Caution) is a 1989 Indian Malayalam-language investigative thriller film directed by K. Madhu, starring Mammootty, Mukesh and Jagathy Sreekumar.
Ekalavyan is a 1993 Indian Malayalam-language neo-noir action thriller film directed by Shaji Kailas and written by Renji Panicker, starring Suresh Gopi in the lead role along with Siddique, Geetha, Narendra Prasad, Vijayaraghavan, Ganesh Kumar, Janardhanan, Madhu, Maathu, Jagathy Sreekumar, Kuthiravattam Pappu, and Devan in other pivotal roles. The plot revolves around a cop named Madhavan, who is hired by the CBI to investigate a godman, who is suspected of being involved in narcotics business and murders.
Ammayane Sathyam is a 1993 Malayalam film written and directed by Balachandra Menon. The film stars Mukesh, Annie, Balachandra Menon, Narendra Prasad, Jagathy Sreekumar, Ganesh Kumar, Thilakan, K. P. A. C. Lalitha, Paravoor Bharathan, Prem Kumar, and Mammukoya. Balachendra Menon remade the film in Tamil as Kandaen Seethayae, however the project was later shelved. He also introduced actress Annie through this film.
Oru Abhibhashakante Case Diary is a 1995 Indian Malayalam-language mystery legal drama film directed by K. Madhu and written by S. N. Swamy.The film stars Mammootty, Heera Rajagopal, Jagathy Sreekumar, Vijayaraghavan, Rajan P. Dev and Narendra Prasad. The plot is about a lawyer, seeking justice for a teenage girl who was raped and murdered. The film has soundtrack composed by Raveendran while the background music is scored by Rajamani.
Sreenath was an Indian film and television actor. He has acted in many Malayalam films, including Shalini Ente Koottukari, Ithu Njangalude Katha, Oru CBI Diary Kurippu, and Kireedam.
Pothan Vava is a 2006 Malayalam film directed by Joshiy starring Mammootty and Usha Uthup. Famous Indian pop and bollywood singer Usha Uthup made her first screen appearance through this film. She played the role of Mammootty's mother. The film was released on October 21 coinciding with Diwali. Pothen Vava performed well and commercial success of Mammootty and decent year of movie
Nair Saab is a 1989 Malayalam language action thriller film, written by Dennis Joseph and directed by Joshiy and produced by Liberty Productions. It stars Mammootty, Suresh Gopi, Mukesh and Geetha. It was released on the occasion of Onam. Nair Saab was one of the biggest blockbusters of Mammootty's career and established his super stardom
Dhinarathrangal is a 1988 Malayalam film written by Dennis Joseph, directed by Joshi and produced by S. V. Krishna Reddy and starring Mammootty, Sumalatha, and Mukesh. The score and soundtrack were composed by Shyam. The film was inspired by the Hindi film "Achanak", (1973).
CBI is an Indian Malayalam-language film series of mystery films directed by K. Madhu and written by S. N. Swamy featuring Mammootty as Sethurama Iyer, a Central Bureau of Investigation (CBI) officer in the title role. The series started off in 1988 with Oru CBI Diary Kurippu. The character Sethurama Iyer is said to have been inspired by a police officer named Radha Vinod Raju, who in 2009 was appointed as the first chief of India's National Investigation Agency.
S. Narayana Swamy alias S. N. Swamy is a screenwriter and actor who works in the Indian film industry predominantly in the Malayalam cinema. Having born in Kochi, Kerala Swamy is particularly known for scripting films in the thriller genre. He has frequently collaborated with directors K. Madhu, Joshiy and A. K. Sajan.
Adimakal Udamakal is a 1987 Indian Malayalam-language political film directed by I. V. Sasi and written by T. Damodaran, starring Mammootty, Mohanlal, Nalini and Seema. Ratheesh, Mukesh, Urvashi, Jagathi Sreekumar, Captain Raju, Lissy, Sukumari and Santhakumari plays supporting roles.
Ithile Iniyum Varu is a 1986 Indian Malayalam-language film, directed by P. G. Viswambharan. The film stars Mammootty, Mukesh, Dipika Chikhlia and Thilakan in lead roles. The film had musical score by Shyam. It was remake of 1984 Hindi film Mashaal.
Kaanathaya Penkutty is a 1985 Indian Malayalam mystery thriller film, directed by K. N. Sasidharan. The film follows the mystery of a missing girl, featuring Bharath Gopi, Jayabharathi, and Mammootty. Thilakan and Jagathy Sreekumar also appear in prominent roles, while Ramachandran and V. K. Sreeraman play the investigators. The film has musical score by Jerry Amaldev. The film was based on a true incident that happened in Thrissur in the year 1979 where a girl went missing and the same revealed the illegal relationship of her mother. It was Sasidharan's second film after Akkare (1984).
Kadamattathu Kathanar is an Indian Malayalam-language supernatural drama television series which was originally aired on Asianet from 2004 to 2005. Asianet retelecast the series on Asianet Plus channel from March 2016. Prakash Paul plays the title character.
CBI 5: The Brain is a 2022 Indian Malayalam-language mystery thriller film directed by K. Madhu and written by S. N. Swamy. The film stars Mammootty reprising his role as CBI officer Sethurama Iyer along with an ensemble cast. It is the fifth installment of CBI film series.