Nicolas Sarkozy's close political ally Claude Guéant is at the centre of a major political controversy over a mysterious payment made to him of 500,000 euros. The former interior minister has angrily denied that the bank transfer payment, unearthed by detectives investigating the alleged Libyan funding of Sarkozy's 2007 presidential campaign, relates to money from the former regime of Colonel Gaddafi. He insists the money came from the sale of two oil paintings by a 17th century Dutch artist. Yet art experts say the two paintings are worth nowhere near 500,000 euros. And if he did sell them abroad as suggested, Guéant appears not to have got the necessary authorisation from the ministry of culture. In another twist, the former civil servant claims other cash payments are explained by undeclared work bonuses he received from 2002 – yet this system of bonuses was abolished in 2001. Dan Israel reports on the tangled web surrounding Sarkozy's former right-hand man.