Col Richards, one of Australia's leading breeders, owners and yearling sales operators for five decades, has died aged 84.

Richards is best remembered as the owner of Mackinnon Stakes winner Oliver Twist and top racemare Hooplahannah but he had hundreds of winners during his long association with racing.

His first major venture in Queensland racing was the popular stud Rosemount Lodge but for the past two decades he has run the famous Gainsborough Lodge on the Darling Downs.

Gainsborough Lodge was originally built for owner-breeder Alfred Grant to house his massive operation in the early 1970s but Grant's empire collapsed soon after.

Richards was able to restore it to its former glory in the 1990s.

He stood many good sires but the best known were the Australian Cup winner Crewman and the prolific win-getting stallion Call Report. His most recent sire Immovable Option has sired the winners of about 200 races, mostly in Queensland.

Richards ran the Brisbane Bloodstock sales, the second largest in Queensland, for 11 years before he closed it last year to concentrate on his breeding interests.

Legendary Queensland jockey Pam O'Neill, who worked for Richards for many years, said racing had lost a true friend.

"Col was known right across Australia as a straight shooter and good bloke. You wouldn't have had a better boss and he knew the game backwards," O'Neill said.

Son-in-law Craig Wallis said Richards had lunch with his family on Sunday and was in fine form.

"It was a shock to us and will be a shock to many in the racing industry," he said.