Ladbrokes announced it had stopped taking wagers after a flurry of unusual activity on the BBC cooking show.
The bookmaker noticed suspicious play on one contestant, whose odds started at 12/1 and were reduced to 6/1, 3/1 and then evens.
Many of the bets were placed in shops around Ipswich, although the contestant is not known to have links to the town.
Several of the wagers were the maximum the bookies would take for the show, and 90% were placed on one contestant.
Ladbrokes said several customers came in and asked to place the highest amount possible on one contestant which raised suspicion.
The first episode of the new series was the most watched opener in the show’s history, it emerged today.
Some 9.3 million viewers tuned in to see professional musician Stuart Henshall become the first contestant to be sent home.
The 35-year-old was eliminated after failing to impress judges Paul Hollywood and Mary Berry with his Black Forest gateau, which he made using beetroot.
Mr Henshall said: “In the future I will make Black Forest gateau my way, in the show I covered it in Italian meringue and I put beetroot in it.
“Maybe I should have made it in more a traditional way for Mary. She is awesome and I have followed her recipes for years and Paul’s but hey, I’m not that traditional myself.
“They are both inspirational, and my personal heroes, even if they didn’t like my cake.”
He added: “My worst moment was definitely being the first to go out, after the excitement of getting there. Somebody has to go first and overall it has been a great experience, without a doubt.
“I felt disappointed in myself initially after leaving in the first episode, as I felt I didn’t perform as well as I could. I just hope I don’t disappoint people in my life, but it’s onwards and upwards.”
Mr Henshall got off on the wrong foot by giving his signature Madeira cake a thick caramel glaze, which stuck Hollywood’s teeth together. The judge told him: “The flavours are all wrong, really.”
He was kicked off the show despite fellow contestant Dorret Conway being sure she would be going home after her gateau failed to set.
The 53-year-old accountant from Preston was reduced to tears when the confection collapsed into a mess on the cake stand.
Despite getting the boot after a week, Mr Henshall thinks he will be recognised for his distinctive “hipster” style.
He said: “It will be weird if I am recognised. I have been known from my band but to be seen in such a different light will be very new and exciting.
“If I don’t wear my trilby perhaps I won’t be recognised.”