6 people will now appear in court on Monday charged with manslaughter following the killing of New Zealand policeman, Kali Fungavaka, in Nuku'alofa last month.
Mr Fungavaka died in hospital six days after he was assaulted while in custody.
A civilian, Semisi Manu, who shared a cell with Mr Fungavaka, was already facing a manslaughter charge.
Three more police officers were charged on Thursday while two of their colleagues who had been charged with common assault have had their charges upgraded to manslaughter.
The Police Commissioner, Grant O'Fee, says there is little he is able to say about the involvement of the 3 officers charged yesterday.
"We are still facing a court proceeding but they were all working that night. One of them is a senior member, a commissioned officer in the Tongan police, and they were all on duty that night. Beyond that obviously I am reluctant to go."