Francois Hollande seeks to defuse row over Nice security

French President Francois Hollande has sought to defuse a row over allegations his government tried to alter a security report after the Bastille Day massacre in Nice.

A probe into the claim should be allowed to run its course, Hollande yesterday said, declaring the truth would be established "(by) the law and no one else."

"Truth and transparency are essential in a democracy," he added.

At the centre of the storm is Interior Minister Bernard Cazeneuve, who right-wingers accuse of security failings after France suffered its third major terror attack in 18 months.

84 people were killed when a truck driven by a 31-year-old Tunisian ploughed through a holiday crowd on the Nice seafront on July 14.

Pressure on Cazeneuve intensified when a local police officer, Sandra Bertin, accused his ministry of trying to bully her into altering a report on police deployment on the night of the attack.

Prime Minister Manuel Valls waded into the affair on yesterday, telling French TV the row was "purely political and aimed at destabilising the government."

While "obviously we need the truth", the row should stop, he said, defending Cazeneuve as "a man of integrity, a statesman, and a great interior minister."

Cazeneuve filed a defamation lawsuit against Bertin, saying her accusations were "likely to give birth in the public mind to the idea that the ministry and the minister have communicated false information" regarding the Nice massacre.

According to the complaint, her words "attack the honour and reputation" of the national police and the minister.

A national police report into the bloodbath had said Mohamed Lahouaiej Bouhlel forced his lorry onto the sidewalk to avoid a police barrier.

But Bertin, who was in charge of the video surveillance system in Nice on the night of the massacre, said on Sunday she was told to describe a police presence that did not match what she had seen on the security camera system.

Bertin said she had been "literally harassed the entire time" that she wrote the report.

"I was asked to change things," she told a news conference, adding that she was ordered "to put in the specific positions of the national police, which I had not seen on the screen".

Bertin is a strong supporter of opposition Republicans regional leader Christian Estrosi and has fiercely criticised the Socialist government through social media networks, Le Parisien newspaper reported yesterday.