The former Ukip leader used his slot on LBC last month to suggest the Swedish city of Malmo saw the highest number of rapes carried out across the continent, and blamed it on “EU migrant policies”.
Ofcom is now assessing Mr Farage’s comments, which went unchallenged at the time but later sparked nine complaints.
An Ofcom statement said: "We are investigating whether comments made in this programme were materially misleading."
Mr Farage told listeners to his 20 February show: “Pro-rata Sweden has taken more young male migrants than any other country in the Europe.
“And there has been a dramatic rise in sexual crime in Sweden – so much so that Malmo is now the rape capital of Europe, and some argue, perhaps the rape capital of the world.
“And there is a Swedish media that frankly just doesn’t report it.”
That claim was widely contradicted by experts, such as Philip N Cohen, a sociologist at the University of Maryland, who produced a graph showing rapes recorded by police per 100,000 population in Sweden compared to the country’s refugee population.
It showed rape figures started increasing after 2004, eight years before the refugee population started increasing in 2012.
Mr Farage, 52, began hosting an hour-long, week-night phone-in on LBC radio in January.
The MEP landed the job after having been by tipped by Donald Trump as a potential ambassador to Washington.
His remarks echoed those of Donald Trump, who used a rally in Florida to list parts of Europe hit by terror attacks.
He then told his supporters: “Look at what’s happening last night in Sweden.”
However, the US President’s comments did not go unchallenged, as there were no reports of an attack having happened in the country.
One Swedish tabloid instead listed the things that really had happened, including an avalanche warning and police chasing a drunken driver.Reuse content