PARIS (Reuters) - The French interior minister has ordered police in western France to take action against a mayor and lawmaker who allegedly told a group of itinerant Roma, parked illegally near his town, that Hitler had not killed enough of them.

Gilles Bourdouleix of the UDI centrist party was recorded by a local newspaper reporter making the comment during an altercation with the group, which had parked more than 100 camping cars on a field near Cholet without a permit.

His remarks were reported as President Francois Hollande moves to defuse growing anger over illegal Roma camps from conservatives and frustrated taxpayers, who, in a time of austerity, feel that social services provided by the state are being abused.

The mayor told a television channel that his comments had been distorted. He was not immediately available for comment to Reuters.

"I mumbled something like, 'if it was Hitler he would have killed them here', meaning, 'thank goodness I'm not Hitler and so there's no reason to call me Hitler," he told BFM news TV. "This is shameful score-settling which aims to smear me."

Last week, Hollande's Socialist Party proposed a law making it easier to evict such groups, amid worries that the issue could prove damaging to his unpopular government in municipal elections one year from now.

"This is not a slip of the tongue," Interior Minister Manuel Valls told news channel i>Tele TV.

"A case has been brought before the courts because this is praise for the crimes of World War Two, it's praise for Nazis, and coming from a mayor it's unbearable," he said.

At Valls's request, a police prefect in western France filed a complaint with a state prosecutor, accusing Bourdouleix of 'praising crimes against humanity', police said.

The prosecutor was not immediately available for comment. A person found guilty of praising crimes against humanity can face up to 45,000 euros in fines, a year in jail, or both.

France numbers about 250,000-300,000 itinerant Roma, mostly French citizens. They have a special status that allows them by law to temporarily park their mobile homes in designated open-air areas with power and water hook-ups during the summer.

But reports of them parking elsewhere - sometimes on municipal sports fields - has angered many.

Earlier this month, the center-right mayor of the southern city of Nice expelled one group from a sports field, vowing to "crush" the "delinquents", and urged other mayors to revolt against what he called leniency by the Socialists.

The head of the UDI, Jean-Louis Borloo, has said he would seek to exclude Bourdouleix at the next meeting of the party's executive committee, according to media reports.

Under Hitler's rule, Nazi Germany attempted to exterminate the Roma people of Europe. Estimates of how many were killed in Nazi concentration camps range from 220,000 to 1,500,000.

(Reporting By Chine Labbe; Writing by Nicholas Vinocur; Editing by Raissa Kasolowsky and Angus MacSwan)