Police investigate French far-right leader Marine Le Pen after she 'tweets graphic images of Islamic State violence'

French far-right leader Marine Le Pen is being investigated by police after allegedly tweeting graphic images of violence committed by the so-called Islamic State group.

The pictures reportedly included the decapitated body of US journalist James Foley.

Mr Foley, a freelance journalist, was captured in Syria in 2012 and beheaded in a video released in August 2014.

While that picture now appears to have been deleted, other shocking pictures - including a man on fire in a cage and someone being run over by a tank - today remained on her page.

They were tweeted with the caption "Daesh is this" - using the Arabic acronym for Islamic State which has been adopted by world leaders.

The prosecutor's office in the western Paris suburb of Nanterre has confirmed it had launched an investigation into "the dissemination of violent images".

Le Pen addressed her tweets to journalist Jean-Jacques Bourdin, a journalist for BFMTV, whom she accused of drawing comparisons between her National Front party (FN) and the militant group and demanding an apology for the "unacceptable insult".

French Prime Minister Manuel Valls called the images "monstrous", accusing her of inflaming public debate and showing no respect for the victims.

Interior Minister Bernard Cazeneuve reported the tweets to the police.Calling the photos "Daesh propaganda", he said Le Pen's messages were "a disgrace, an abomination and an absolute insult to all victims of... Daesh".

Undeterred, Le Pen tweeted again, challenging Cazeneuve to try to sue her for defamation of Islamic State.