Worried that punters had inside information Coral reduced its odds from 20-1 to 7-1 to 2-1 in a single day after it was inundated by would-be punters trying to place bets.

"We are wondering whether people with inside information about the contestants know that sex is a distinct possibility this time round," spokesman Simon Clare said.

"A Big Brother bonk will cost us a fortune."

While it would clearly make the randy devils a small one.

"If the money is any guide you can expect 12 nymphomaniacs to be let loose in the house."

Clare said hundreds of bets had been placed on the issue, including some three-figure bets.

Other bets being placed before the contestants have even been unveiled include whether it will be won by a man or a woman.

The previous two winners have both been men and Coral is offering 4-9 odds on a male winning the £70,000 prize money, with the female contestants lagging behind at 13-8.

It is also offering 4-1 on a contestant quitting, 12-1 on the winner not being one of the first 12 contestants and 8-11 on the first evictee being female.

Let the madness begin.