A new US reality TV show starting next month features 20 women tricked into competing to marry a penniless builder posing as a millionaire.

The contestants in Joe Millionaire - filmed in secret in France - believe the American playboy has inherited $50m (�32m). He actually has an annual income of $19,000.

In the end, he must reveal to her that he's basically broke Mike Darnell Fox reality TV chief

Fox TV, which screened the controversial Who Wants to Marry a Multi-millionaire two years ago, has billed the new show as the "gold diggers and the ditch digger".

The 20 single women are flown to France to win the bachelor's affections, where they are treated to gourmet meals and horse riding in the grounds of what they think is his chateau.

But viewers will know from the start that Joe's bank account is empty.

Quest for true love

Fox TV will launch the seven-episode series on 6 January.

Contestants have a romantic time in Paris

The show will "rip the mask off" people who compete in such programmes, according to Mike Darnell, head of reality TV at the network.

"We find out whether they're really doing this for love."

Joe will give each of the losing women items of jewellery of escalating value as he narrows down his list of potential partners.

He will be honest about other aspects of his life, including past romances, while concealing his poverty.

In the final episode, he will select the one woman with whom he wants to have a relationship.

If she agrees, Joe will have to tell the truth.

"In the end, he must reveal to her that he's basically broke," said Mr Darnell. "We get to see if she still wants to be with him. It's a spectacular show with a spectacular ending."

According to Fox Entertainment president Gail Berman, quoted by Reuters news agency, "it's a great spin on these kinds of shows and reality TV in general".

She says it will "cause some controversy and hopefully grab some viewers".

Kept in the dark

But Joe Millionaire will be a one-off series, she adds.

ABC screened a similar show which became a huge hit in the US this year - The Bachelor, in which women competed to marry a rich man.

Joe Millionaire was filmed under tight security to prevent any of the women discovering the truth.

Most of the production team and the butler hired to act as Joe's assistant were also led to believe that he was a real millionaire.

The series was made by the same company that produced Temptation Island, where couples were separated at a luxury resort and had to deal with the advances of models out to seduce them.