Jeyaraj, 59, and his son Beniks, 31, were arrested onJune 19.
Four Tamil Nadu policemen have been arrested in the custodial deaths of two men in the town of Tuticorin - a father and son allegedly tortured by cops after keeping their shop open 15 minutes longer than allowed amid the coronavirus lockdown.
Inspector Sridhar, sub Inspectors Raghu Ganesh and Balakrishnan and constable Murugan have been arrested by the Crime Branch of Tamil Nadu's CID (Criminal Investigation Department) under relevant sections of the Indian Penal Code (IPC).
"FIRs have been altered to 302 IPC. 12 special teams under IG and SP (CB-CID) are investigating all angles," Shankar, Inspector General (CB-CID) told NDTV.
The CB-CID has modified both FIRs - one each for the death of the father, Jeyaraj, and the son, Beniks - and to include murder charges against two sub inspectors (Raghu Ganesh and Balakrishnan), two constables and two other individuals.
The police had earlier only registered cases of suspicious deaths.
The Madurai bench of the Madras High Court, which conducted its own inquiry into the shocking incident, had asked the CB-CID to take over the case from Tuticorin Police until the CBI, to whom the case has been handed over, takes charge.
On Tuesday the court noted that based on post-mortem reports there were grounds to charge the three policemen allegedly involved in the deaths with murder.
The court was also told that CCTV footage that could provide throw light on what happened at the Sathankulam Police Station on June 19, when the two men were arrested and allegedly tortured, had been deleted.
The court then initiated contempt action against three cops, including a Deputy Superintendent and an Additional Deputy Superintendent, after the judicial magistrate who conducted the inquiry accused them of trying to obstruct his inquiry.
However, a key witness - a Head Constable - then testified to the brutal attack and the role of the police. Fearing that either the witness or the witness' family could be intimidated, the court asked the police to provide security.
The case, which has generated waves of outrage across the country and prompted actor-politician Kamal Haasan to describe Tamil Nadu Chief Minister Edappadi K Palaniswami as a "prime accused", was handed over to the CBI this week.
In an official statement on the incident the Chief Minister and his deputy, O Pannerselvam, called the deaths "very unfortunate" and vowed justice to the family members.
Jeyaraj, 59, and his son Beniks, 31, were arrested on June 19 for keeping their mobile phone shop open 15 minutes longer than allowed during the lockdown. The police claimed the two fought, verbally abused and resisted arrest.
The family has alleged the two men were subjected to brutal torture while in police custody, pointing out severe internal and external wounds, including rectal bleeding, to back their claims.
Beniks was admitted to hospital at 7.45 PM on June 22. He died at around 9 PM, according to a timeline released by the police. His father was admitted around 10.30 PM the same night and died around 5.40 AM the following day.