A third man has been arrested and is being questioned over the murder of an off-duty policeman in Stockport in the early hours of Sunday.
Two other men were arrested on Sunday by officers investigating the death of PC Gareth Francis.
PC Francis was found with a serious head injury at around 1.20am on Sunday in the Stockport suburb of Edgeley, Greater Manchester, after police were called to a report of an assault.
Paramedics treated the officer, who was not working at the time, and he was taken to Stockport's Stepping Hill Hospital where he later died.
The latest man to be arrested handed himself into a police station on Sunday night where the 20-year-old was arrested on suspicion of murder.
Greater Manchester Police have been granted more time to question the first two men, aged 20 and 21, and have until 5pm to charge them or ask for more time.
PC Francis was described by his family as a "gorgeous son" who brought "love and laughter" into their lives.
"He was an amazing brother, boyfriend, grandson and nephew," they added, in a statement released through Greater Manchester Police.
"We cannot imagine how we can face each day knowing that he is gone from our lives."
A post-mortem is due to take place to establish the cause of death.
PC Francis joined Greater Manchester Police in 2007 and at the time of his death was serving at West Didsbury Police Station in south Manchester.
Stockport's divisional commander, Chief Superintendent Chris Sykes, said: "First and foremost I would like to pass on my condolences to both Gareth's family and his colleagues in south Manchester.
"Gareth was a dedicated police officer with six years' experience and he will be greatly missed by his colleagues.
"However, the loss will be even greater for Gareth's family and I would like to reassure them that we have a team of detectives working round-the-clock now to establish exactly what happened."