MG George Muthoot, father of Paul M. George who was found killed under suspicious circumstances near Alappuzha in August, on Friday approached the Kerala High Court seeking a Central Bureau of Investigation (CBI) probe into the killing.
The court is expected to take up the petition in the coming days.
George, 32, was killed Aug 21 while travelling in a car with Om Prakash and Rajesh, both of whom have criminal records.
This is the first time that the family came out in the public since the murder. In his petition, George's father highlighted 18 points in the manner in which the present probe by the Kerala police is going on, claiming the investigation is "based on a pre-written script".
In the petition, he has said that police used TV channels to "propagate false theories" in the murder, alleging this was meant to help the real culprits escape.
He called for a detailed examination of the "real" culprits' political links and relations with people outside the state. He also claimed that the testimony of Manu, friend of George who was in the car at the time of murder, and of George's driver was not convincing and hence, only a CBI probe would bring out the real truth.
Police have arrested 19 people for their involvement in the murder. These include Om Prakash and Rajesh. The mother of accused K.Satish had earlier approached the court for a CBI probe.
The court then turned it down, saying that the investigation was on and she could raise the same demand later.
Last month, the Congress' state unit chief Ramesh Chennithala said the probe into the murder has been "bungled completely" and as people have lost faith in the Kerala police, a CBI probe should be ordered.