The star, who plays outgoing Slater patriarch Charlie, was found not guilty in an Old Bailey trial of stealing £10,000 of meat while working at a meat market in London in 1961.
However, Martin told Celebrity Mastermind host John Humphrys that he had in fact taken the produce - although he never got to enjoy the goods.
As the soap actor prepared to answer general knowledge questions on the show, Humphrys asked: "Didn't you once convince a jury that you hadn't pinched some meat from Smithfield?"
Martin replied: "Yes, a long time ago in 1960-odd, yeah... £10,000 pounds worth, yeah."
When asked if he felt guilty over the theft, he responded: "No, I was just choked I never got the meat."
He added that a female jury member had congratulated him on his "performance" in the dock, and suggested a career in acting.
A number of viewers are reported to have complained to the BBC over the admission.
According to the Daily Mail, one viewer commented: "It was a primetime slot on the BBC and there was a villain bragging about his crimes.
"The BBC should not be helping glorify crime because there might well be impressionable people watching."