A 12-year-old boy is among four people arrested following a murder on Christmas Eve.
Matthew Goddard, 41, was found beaten to death in his home in east Belfast in what police described as a sustained and brutal attack.
His electric guitar was reportedly used in the assault.
A 21-year-old man and a 24-year-old woman who were arrested on Saturday - four days after Mr Goddard was found murdered - remain in custody.
Detective Chief Inspector John McVea revealed that detectives from the PSNI Serious Crime Branch carried out searches in the east of the city today and arrested a 17-year-old and the 12-year-old boy.
Both have been taken to Musgrave custody suite in the city where they are helping police with their inquiries.
A number of searches in relation to the investigation are ongoing in the east Belfast area, the PSNI said.
Mr Goddard's body was found in the living room of his home on Chobham Street at about 9.40pm on Wednesday. He had not been seen alive since 6pm the previous day, December 23.
Police said he may have been involved in the drugs trade and that while it was one of a number of lines of inquiry being pursued by detectives, they did not have a motive for the murder.