Mrs Chelski ... the £11bn work experience girl

As the wife of the 11th richest man in the world, it would not be unusual to see Irina Abramovich in one of London's more exclusive hotels, taking tea in the lobby or perhaps enjoying a glass of champagne at the bar.

But when 39-year-old Irina recently paid a number of visits to the chic Mayfair establishment Brown's, it was not as a guest - but as an undercover trainee.

The elegant Russian, whose husband, Chelsea FC owner Roman, is worth more than £11billion, has embarked on secret 'work experience' at the five-star hotel.

Guests have not been told the identity of the perfectly manicured blonde who has been attending to their every need. And her presence in the hotel has been kept on a strictly need-to- know basis, limited to a small number of key executives.

"Irina is planning to set up a chain of boutique hotels in England and Europe and expects her husband to fund the venture," said a source close to the couple. "Irina always was a very hard-working person and now she's bored. She wants a project. She's as tough as her husband."

Even for a man of Abramovich's means it is - as his wife intended - a hefty price to pay for his alleged dalliance with the beautiful 23-year-old Russian model Daria Zhukova.

Wealthy family

Last week it was revealed that Irina has consulted Britain's top marital lawyer Raymond Tooth. But a spokesman for Abramovich, 39, denied the allegations and insiders insist a divorce is by no means inevitable.

However, the situation has created an opportunity for Irina, who has spent most of her time bringing up the couple's five children.

With her husband on the back foot, she has decided to carve out a career in the form of her own hotel empire. Her friend, Olga Polizzi, the 59-year-old hotelier, designer and sister of Brown's owner Sir Rocco Forte, has been advising her.

In public at least, the project symbolises a new, independent Irina but the couple have led separate lives for years. They married in 1991 after meeting while she was working as an air hostess for Aeroflot.

It was his obsession with work that split up his first marriage, but Irina, who was born into poverty, would prove more understanding.

Former Aeroflot colleague Larisa Kurbatova said: "Irina told me, "My children will never suffer like this. I'll do everything so they are brought up in a wealthy family."'

Last night a spokesman for Brown's said: "I don't know anything about this so can't make any comment. It would be a personal matter between Ms Polizzi and Mrs Abramovich."

And John Mann, a spokesman for the Abramoviches, said: "This is not the case. She doesn't even visit the hotel very often."