A reward of up to £20,000 is being offered for information leading to the arrest and conviction of those responsible for the murder of a man in Warwickshire.
Adam Lucas, 51, was found dead in the river at Victoria Park in Leamington Spa on April 15.
A post-mortem examination found that he had suffered injuries consistent with being assaulted.
As the investigation reaches six months since his death, Warwickshire Police said detectives believe someone may still have crucial information about what happened.
Four suspects remain on bail
Three people arrested on suspicion of murder — a 27-year-old man from Birmingham, a 44-year-old woman and a 43-year-old man from Leamington — remain on police bail.
A 23-year-old woman from Birmingham, who was initially arrested on suspicion of assisting an offender and later arrested on suspicion of murder, has also been bailed.
A 53-year-old man from Leamington who was arrested on suspicion of murder has been released with no further action.
No one has been charged in connection with Mr Lucas’s death.
Detective Inspector Gareth Unett said: “We’re determined to make sure those responsible are brought to justice and we’re confident someone knows what happened.
“With a £20,000 reward now available, we hope those who know something will do the right thing and come forward.”
The reward is being offered by the independent charity Crimestoppers and is subject to its terms and conditions.
Anyone with information can contact Crimestoppers anonymously on 0800 555 111 or through the charity’s website.