A post-mortem examination on the body of a man found dead in a Hartlepool has proved inconclusive.
Police were called to the sudden death of a man, named locally as Martin Strickland, 41, at an address on Church Street in the town at around 2am on Tuesday.
It is believed his body was discovered by a friend.
A post mortem carried out yesterday has proved inconclusive and further tests will now be carried out to try to establish the cause of death.
Officers are continuing to treat the death as unexplained and enquiries are ongoing into an earlier incident during which it is believed that the man could have been assaulted.
Four people arrested by officers in connection with the earlier possible assault have now been released with no further police action, a spokeswoman for Cleveland Police said.
A 33-year-old man who was arrested on suspicion of assault, robbery and possession with intent to supply class A drugs has been released under investigation.
Paul Edwards, director of Asset Property Management, which looked after the flat, said the death of the 41-year-old had come as a huge shock.
He told the Mail: “It is a terrible shock.
"We always found Martin to be a lovely lad.
"He was no bother as all, his rent was always paid on time.
“He had been a tenant for coming up to a year and was a really nice lad.
"It is very, very sad.”