The cult show has now been on the American screens for five weeks, with the audience levelling off to eight million last week.

Many critics gave the show a frosty welcome

The move to increase the show's output in the autumn means it will no longer face competition from Who Wants to be a Millionaire, another British quiz export which is shown on NBC's rival ABC up to five nights a week.

Robinson expected such success. Her husband John Penrose told the New York Post last month that he and Robinson were planning to buy a house in New York because they would be spending so much time there.

In April NBC announced that it was doubling the run of the show to 26 episodes.

Traumatised contestants

But Robinson has failed to impress the critics. The New York Post noted that while she is billed as a formidable dominatrix, "with her practical cropped hair and glasses, she is more like a school librarian".

Her performance seems to have been enough to traumatise the US contestants, however.

Last week the UK Star newspaper reported that humiliated American Weakest Link contenders are given free therapy to help them deal with Robinson's viper-sharp tongue.

Robinson mixes glamour with terror

The ordeal could be worth it. Prizes on the American version of the show are higher than in Britain, with up to $1m (�705,000) to play for.

No-one has so far managed to take home the jackpot, with winnings typically at around $100,000 at each show.

Another British quiz show, Dog Eat Dog, which has a similar premise to Weakest Link, has also been sold to the US. But host Ulrika Jonsson said it was unlikely she would be presenting the US version.

"I shouldn't think they will want me. They have Anne Robinson and she's nastier."