"Something snapped in me," says shamed chef Antony Worrall Thompson, who had gone on a shoplifting spree over the Christmas period, and arrested by the police on Friday based on evidence by a Tesco supermarket.

The "Ready, Steady, Cook" celebrity chef says he could not believe what he has done and fears dementia could be hitting him early in his life.

Thompson became quite an icon in the industry in the early 1980s when he opened a restaurant called Ménage à Trois in London's elite Knightsbridge.

"I hope I'm not going totally gaga in my old age ... I have wondered if it's something like that, but I hope 60 is too young for something like Alzheimer's," he told the Daily Express.

Thompson had been stealing from Tesco for a couple of times before the supermarket gathered enough evidence to positively identify him. He was arrested after his fifth thieving incident, said the reports.

The goods Thompson had reportedly stolen groceries that amounted to £70.68 (AU$105).

More than anything, the chef is worried over the stability of his mental faculties, as he kept saying he could not believe what he has done. He also told the Daily Express he feels ashamed for his wife and two children and would consult with psychoanalysts.

Thompson says he has been a Tesco customer for years and has known many of the staff at the Henley branch in which he was caught stealing.

Despite getting badly affected by recession in 2009, during which he closed four of his restaurants and sold his house for £3.2 million (AU$4.8 million), Thompson had reportedly said he was still comfortably well-off.

The Daily Mail reported an instance in which Thompson stole £4 (AU$6) in Tesco groceries while paying £180 for three crates of champagne.

Thompson's five incidents of theft happened within 16 days, starting just before Christmas.

Asked whether the stress of his work schedule has taken its toll on him, he said he could not tell that for sure.

"Why did I do it? I've been asking myself the same question ever since Friday," he said.

"I don't understand why. I've been racking my brains to think why on earth did I do it and what was going through my mind at the time, but I just don't know."

In a published statement, Thompson says:

"I am so sorry for all my recent stupid and irresponsible actions; I am of course devastated for my family and friends, whom I've let down and will seek the treatment that is clearly needed."

Thompson is certainly not the first and arguably not the biggest celebrity to have been linked to shoplifting charges.

In 2002, Winona Ryder, who had been known for bouts of depression, was convicted of theft for shoplifting in a Los Angeles department store.

Just last year, Lindsay Lohan was sentenced to 360 hours community service for stealing a gold necklace from a jewellery store in the U.S.