The French government was forced to admit that no one was safe from internet fraud yesterday after it emerged that thieves had managed to hack into President Nicolas Sarkozy's personal bank account and siphon off cash.

The unknown hackers removed several small sums of money from the account after obtaining Sarkozy's online access codes. An inquiry was launched after the president noticed the transactions and complained to the police, said a government spokesman.

"The swindlers will be punished," Luc Chatel, secretary of state for consumer affairs, told French radio. He said more work needed to be done to tighten internet banking security in France, which, according to the national crime agency, has seen a 9% rise in offences this year.

"[This] proves the system of internet checking [of bank accounts] is not infallible," Chatel said. "These cases are sufficiently rare that we haven't had to really organise ourselves, but [they are] sufficiently serious for us to reflect on how to improve the system."

Breaking the news of the thefts yesterday, the Journal du Dimanche newspaper said the architects of the "presidential piracy" did not appear to be amateurs.