Paris: France's polling watchdog has issued a warning over what it says is a misleading Russian news report claiming that Francois Fillon, the scandal-hit conservative candidate, has regained the lead in the presidential race.

The Polling Commission criticised a French-language report by Sputnik, a state-run Russian news agency, for presenting a social media survey by Brand Analytics, a Moscow-based online research firm, as a "poll" showing Mr Fillon as the front-runner.

In fact, French opinion polls, which are supervised by the authorities, show Emmanuel Macron leading on about 26 per cent, with Marine Le Pen, the Front National leader, one point behind.

Mr Fillon is currently polling in third place, on 19 per cent. If he comes third in the first round of voting in three weeks, he will be eliminated from the second and final vote next month.

In a statement, the watchdog said the survey could not be described as representative of public opinion and that Sputnik had improperly described it as a "poll" because it did not fulfil the legal definition of the term under French law.

"It is imperative that publication of this type of survey be treated with caution so that public opinion is aware of its non-representative nature," the commission's statement said.

Sputnik published a similar online survey by the same firm in mid-February, also showing Mr Fillon in the lead while opinion polls were placing him third.

Neither Sputnik nor Brand Analytics responded to requests for a comment yesterday.

The unusual cautionary note from the Polling Commission, which monitors pre-election opinion polls, follows multiple allegations of Russian meddling in the French election.

Emmanuel Macron, the centrist candidate, has said he is being targeted by "fake news" put out by Russian media.

Mr Macron backs European sanctions on Moscow over the Ukraine crisis, whereas Mr Fillon has said they are ineffective and create a "Cold War" climate. The conservative candidate also favours an alliance with Russia in Syria.

Mr Fillon had been the favourite until he was accused of giving his wife and children "fake" jobs as his parliamentary aides, paying them more than $900,000 ($1,170,000) of public money.

Police in Moscow detained about three-dozen people at unauthorised rallies in the Russian capital on Sunday, a week after anti-government protests broke out across the country.

Telegraph, London