The aristocratic wife of a former aide to President Nicolas Sarkozy has publicly accused her estranged husband of making frequent trips overseas in the 1990s to collect "bags of cash" for illegal political funds.

In her first public comments on a deepening political scandal, Princess Helene of Yugoslavia, 50, also said she had been threatened by her husband with losing custody of her children and "ending in an asylum" if she spoke too freely to independent investigators.

Princess Helene, the great-granddaughter of the last king of Italy, has become one of the key figures in the so-called "Karachi affair" since her husband, Thierry Gaubert, and Nicolas Bazire, another close associate of Sarkozy, were arrested last week and formally accused of handling kick-backs on multibillion-dollar arms contracts.

In interviews at the weekend, the Princess confirmed allegations that she made to police and an examining magistrate this month. She claimed Gaubert, 60, made five or six trips a year to Geneva from 1994-1995 to pick up "bags full of cash", and that Gaubert, who was No 2 in Sarkozy's private office at the time, always returned via London to avoid "custom checks at the Franco-Swiss border".

The Princess said her husband had spoken of handing the bags of money to Bazire, who was campaign manager for the then Prime Minister, Edouard Balladur, when he ran unsuccessfully for the presidency in 1995.

Bazire, now a senior luxury goods executive, was best man at Sarkozy's wedding to Carla Bruni in 2004.

An examining magistrate is inquiring into allegations that the Balladur campaign was illegally funded by kick-backs from commissions on French arms sales to Pakistan and Saudi Arabia. A separate judicial investigation is looking into allegations that the cancellation of the commissions by President Jacques Chirac in 1996 led eventually to a bomb attack on a bus in Karachi in 2002 in which 15 people, including 11 French submarine engineers, died.

The Elysee Palace has rejected as "politically motivated calumny" any suggestion that Sarkozy was linked to illegal campaign financing.I

- Independent