Vincent is understood to be pressing ahead with the social event of the festival on board his Veni, Vidi, Vici luxury yacht moored in Cannes.

Tchenguiz brothers were today in defiant mood and said Vincent's party this evening at the Mipim property jamboree in Cannes would go ahead, just 24 hours after their shock arrest by the Serious Fraud Office.

Vincent and Robbie were questioned by the SF0 yesterday in its investigation into failed Icelandic bank Kaupthing. Vincent is understood to be pressing ahead with the social event of the festival on board his Veni, Vidi, Vici luxury yacht moored in Cannes.

Doubts over the party grew yesterday after the pair were among seven men arrested by the SFO and City of London police. Alongside the Tchenguiz brothers, one of the men is believed to be a former Financial Services Authority employee and treasurer at Kaupthing, Gudni Adalsteinsson.

Vincent was due to fly out to Mipim last night before the arrests but is heading out after travel documents seized in the raid were returned.

Scions of the property world will be on the guest list at tonight's bash on the Jetée Albert Edouard. One delegate at the festival said: "Everybody is still talking about it, although not many were particularly surprised. They're showing that life goes on." Robbie Tchenguiz was one of Kaupthing's biggest clients, racking up £1.4 billion in loans to fund a host of acquisitions including stakes in Sainsbury's and pubs group Mitchells and Butlers, but lost £1 billion in the crash.

He was said to be readying a challenge to the Barclay brothers' bid to buy the Claridge's, Berkeley and Connaught London hotels although the arrests could scupper this. Administrators of Kaupthing are suing the Tchenguiz brothers in the high court,