Ten Loyalist Volunteer Force inmates in the Maze prison are being questioned by RUC detectives about the murder of a fellow prisoner, David Keys, last weekend, it is understood.
The men were arrested yesterday and are believed to have been taken from the jail, outside Lisburn, Co Antrim, into police custody.
A senior LVF prisoner who had been questioned about the killing was freed without charge on Tuesday night. It is understood he has been released from the Maze after completing his sentence.
The arrests came as detectives returned to the LVF wing where Mr Keys (26) was found dead in a cell last Sunday.
He was one of four men on remand, charged with the murders of Mr Damian Trainor and Mr Philip Allen in Poyntzpass, Co Armagh, last month.
He was buried yesterday at Roselawn Cemetery in east Belfast after a private service at a funeral parlour near his Cregagh Road home.
The family had requested no paramilitary trappings or media presence at the funeral. Their Free Presbyterian minister, the Rev David McIlveen, said they were grateful that their wishes had been heeded.
Mr Keys was found dead after being beaten, strangled and strung up in his cell with a bed sheet. His wrists had been slashed. His killers had attempted to make the death appear to be suicide but after the post-mortem examination, the RUC began a murder inquiry.
Mr Keys was a former member of the UVF in east Belfast but he was shot by the paramilitary group two years ago following allegations of involvement in the drugs trade.