A French public prosecutor opened an inquiry Wednesday into a Nazi-themed party at a ski-resort restaurant which cost conservative MP Aidan Burley his job as a parliamentary aide.

The 11 participants in the December party in the resort of Val Thorens in the French Alps risk up to five years in jail and fines of 45,000 euros if a judge decides to summon and try them.

A customer at the restaurant filmed parts of the December 3 party where some of the revellers wore Nazi uniforms and armbands bearing a swastika. They finished the evening off singing Nazi songs and making toasts in the memory of the Third Reich.

The restaurant's manager and anti-racism and anti-Semitism groups filed complaints that led to a preliminary investigation being opened in the nearby city of Albertville.

Investigating magistrates will question witnesses before likely moving in the coming weeks or months to place some or all of the partygoers under formal investigation. Such cases can take years to get to court in France, however.

The Conservative Party sacked Burley in December from his job as a Parliamentary Private Secretary at the Department of Transport for behaving in an offensive and foolish way.

Burley had previously apologised after the Mail on Sunday newspaper published photos of him at the party.

(Reporting by Catherine Lagrange in Lyon; Writing by Leigh Thomas in Paris; Editing by Andrew Roche)