One of Queensland's most popular racehorses Chief De Beers has died aged 28.

Chief De Beers had been in retirement at the Living Legends complex in Victoria after an outstanding career as a racehorse and police horse.

Living Legends turned to social media on Friday to announce Chief De Beers' passing and tributes flowed freely.

He had the unusual record of winning 21 races - all at the Doomben racecourse in Brisbane in the 1990s.

Chief de Beers won every open company feature sprint race at Doomben including two Group One Doomben 10,000s and the Group One BTC Cup.

Although only a small horse, Chief De Beers carried up to 64.5 kg winning at Doomben.

Trained by Bill Calder and owned by the Greenup family, Chief De Beers earned prize money 42 times in his 51-start race career.

He was placed in Group company at five other tracks around Australia but couldn't win.

Chief De Beers later worked a police horse and was recently presented with the prestigious Blue Cross Medal for his service to the community.

The gelding had required ongoing treatment for a long-standing illness before he was euthanised.