“Anyone at the heart of the republic who wanted to know could know,” journalist Edwy Plenel told the inquiry on Tuesday morning.
He and his colleague Fabrice Arfi were the first witnesses to appear before the inquiry, which is a rare initiative in France.
Plenel founded the Mediapart website, which broke the story of Cahuzac’s tax fraud and lying, and Arfi works for it.
He claimed to have met members of Hollande’s inner circle on 18 December, two weeks after publishing the first revelations on Cahuzac.
Both journalists claimed that the police had been set to work to unveil their sources, Arfi adding that they had kept track of Plenel’s telephone calls to one of them.
“We don’t know of the interior minister [Manuel Valls] was personally aware of these inestigations,” he told the MPs.
Cahuzac, who has been charged with tax fraud and resigned as a minister, on Tuesday declared that he “wants to pay [his] debt”, telling RTL radio that he had swindled the fiscal services out of 685,000 euros.
He is writing a book to explain his actions, he said.
Ministers continued to deny that they know what was going on.
“The trugh is very simple: up until the day that Jérôme Cahuzac confessed that he had lied, nobody, I mean nobody, in the government knew,” Budget Minister Pierre Mocovici, who was Cahuzac’s boss, told RMC radio.
Moscovici, Vallas and Justice Minister Christiane Taubira are to appear before the inquiry.
Right-wing politician Michel Gonelle, who made public a tape of Cahuzac discussing the secret account, was set to appear Tuesday afternoon.