The theft of a memorial dedicated to a black man is being treated as a hate crime by police.
The plaque, commemorating British-Nigerian David Oluwale, was taken on Monday just hours after it was unveiled on Leeds Bridge, where he was last seen alive in May 1969.
It was erected in his memory after he drowned when being chased by police.
A jury later convicted two officers - Sgt Kenneth Kitching and Insp Geoffrey Ellerker - of assault in connection with David’s death after they acquitted them of manslaughter.
But they became the first policemen involved in the death of a black person to be successfully prosecuted – in a landmark criminal case.
The special unveiling ceremony, organised by Leeds Civic Trust and supported by the David Oluwale Memorial Association, concluded at 7pm.
It is believed the plaque was likely to have been removed sometime between 9.30pm and 10pm.
Leeds District Commander, Chief Superintendent Damien Miller said: “It is truly appallingly that someone would remove the plaque commemorating the life of David Oluwale.
“We recognise the significant impact that this act will have had on all those involved in keeping David’s memory alive and on the wider community.
“The timing clearly suggests that this has been a deliberately targeted act and we are classing this as a hate crime.
“We are treating this incident very seriously and have detectives from Leeds District CID carrying out extensive enquiries to identify who is responsible and to locate and recover the plaque.
“Leeds Bridge is in a busy area in the heart of the city centre and we would urge anyone who witnessed any suspicious activity or who has any information that could assist the investigation to contact us immediately.”
Anyone with information is asked to contact Leeds District CID via 101 quoting crime reference 13220222118 or online.
Information can also be given anonymously to Crimestoppers on 0800 555 111.