The TV star, who moved to the US to present the American version of Bake Off earlier this year, also hinted he might be getting back together with his wife.
Paul, 47, split with his wife of 15 years Alexandra this summer after it was reported he had an affair with his 35 year-old US co-star Marcela Valladolid.
During a radio interview the famous bread-maker admitted he had ‘deservedly’ been the focus of media attention recently, ‘because of what I did in America.’
He then said: ‘It was the biggest mistake of my life.’
When asked to clarify what he meant, he said: ‘I did have an affair in America with my co-judge. It something which was the biggest mistake of my life, because actually I still love my wife.’
His wife Alexandra has reportedly already begun divorce proceedings, previously telling a UK newspaper there was ‘no going back.’
‘I love my husband and I was and still am very proud of what he has achieved, but there is no going back and I just want this finished with and to move on,’ she said.
But Paul hinted there might be a reconciliation on the cards: ‘I’m at that point at the moment where we’re talking, we are working to get back together again. But it’s going to take time,’ he said.