A potential new witness has been interviewed three times by police investigating the death of a man in the Highlands 21 years ago.
The body of Kevin Mcleod, 24, was found in Wick harbour on 9 February 1997.
His family believe that injuries on his body showed that he was murdered, and have criticised the police investigation into the death.
Police Scotland said a possible witness highlighted by the family has now given a comprehensive statement.
According to the Mcleod family, the man claimed to have heard a commotion on the night of Kevin's death, followed by a splash.
He claimed he saw two people and Kevin in the water but ran away when they spotted him and gave chase.
Police Scotland said the information was being assessed, and further statements have been taken from other people.
However, other lines of investigation suggested by the family have not yielded any fresh evidence, the force said.
Mr Mcleod, an electrician, was last seen alive in the early hours of 8 February 1997 while on a night out with friends in Wick. His body was recovered from the sea the following day.
In December last year Deputy Chief Constable Iain Livingstone made a personal apology to Mr Mcleod's parents over the way the case was previously handled.
He said there had been "serious failings" on the part of Northern Constabulary, and officers had missed "the opportunity to gather vital evidence".
In January the force confirmed that a man had come forward offering new information.
In an update, Det Ch Supt Gareth Blair said officers had now spoken to him "on three occasions and noted a detailed and comprehensive statement".
He added: "The information from the new witness is currently subject to ongoing assessment which has resulted in a number of additional statements being taken from related persons as well as engagement with independent national experts in certain fields."
Det Ch Supt Blair said officers had also searched a number of police stations to gather documents relevant to this new line of investigation.
Some of the other information provided by the family was "historical and has previously been investigated and no evidence found", he said.
In January the Mcleod family and police made a fresh appeal for anyone with information about Kevin's death to come forward.