French actor Gerard Depardieu may find acquiring Belgian nationality a tough business with a senior official saying on Monday that the French tax exile would have to prove a real love for Belgium's culture.

The 63-year-old film star has threatened to give up his French passport over a tax dispute, but Belgium's parliamentary commission that deals with such requests has said it did not receive any demand from Depardieu.

Daniel Senesael, the mayor of Estaimpuis near Nechin, a tiny village just over the French border in Belgium where Depardieu has bought a house, has revealed the actor had called him to inquire about the conditions for nationality.

Depardieu "could be a useful talent for Belgium," said Jacques Dallemagne, the head of the parliamentary body that approves requests for nationality.

But Karine Lalieux, another member of the commission, took a tougher line.

"Gerard Depardieu has to convince us that he does not want to become Belgian only to avoid the French taxman," she said. "He must prove that he loves Belgian culture and wishes to promote it."

"We are wary of rich French nationals who take the Belgian route to be able to finally settle in Monaco," she said of the tax haven on the French Riviera that draws global celebrities.

Belgium's foreign minister said France was solely to blame for Depardieu's tax flight.

Didier Reynders said his country must not be made a "scapegoat" for the move, which the French prime minister suggested was an unpatriotic act.

"There have been no measures taken by Belgium to attract any French national," Reynders said on RTL radio. "There has been an evolution in the French tax system that may have had consequences."

"One must look at the things for which citizens are leaving their own country, even if these are tax reasons," he added.

Earlier, Reynders said many Belgian sports celebrities had sought tax exile in Monaco and that Belgian authorities had accepted that. He also noted that many Belgians shopped in France because of lower value-added tax.

In an open letter to French Prime Minister Jean-Marc Ayrault, who called Depardieu's move "pathetic", the film star said he had been treated unfairly after paying millions of euros in taxes. Ayrault said on Monday the "pathetic" tag did not apply to the actor personally but only the move, "which has a pathetic side to it".

Depardieu has joined some of France's wealthiest business figures in Belgium following moves by President Francois Hollande's Socialist government to tax annual incomes above 1 million euros ($1.3 million) at 75 percent.

Unlike France, Belgium does not impose a wealth tax and has not had one since 1830. Its income and inheritance taxes are also lower.

In his letter, Depardieu, who has extensive business interests including wine estates and three Paris restaurants, accused the Socialists of driving France's most talented figures out of the country.

He said that over 45 years of working and running businesses in France, he had paid 145 million euros into state coffers.

The affair has been seized on by the right-wing UMP party of Hollande's predecessor Nicolas Sarkozy, whose leader, Jean-Francois Cope, said the president, who famously said he did not "like the rich", was destroying the country.

"What I regret above all is how the Socialist government is running the country into the ground," Cope said on Monday, denouncing the "tax bludgeoning which is hitting all French citizens".

"He is in the process of taking our country backward."

France's richest man, Bernard Arnault, came under fire in September when it emerged he had applied for Belgian citizenship. Arnault, the boss of luxury conglomerate LVMH, denied he was seeking to become a tax exile, saying he wanted Belgian nationality "for personal reasons".