Russian authorities on Wednesday were under fire after a TV crew from a Norwegian broadcaster reported repeated harassment while on a trip to Sochi covering the run-up to the Winter Olympic Games.

Journalists from TV2 told AFP they were stopped and questioned multiple times, including on Wednesday, when they were already going to Sochi airport to fly out.

Since arriving to the regional centre Krasnodar on October 21, "there have been so many incidents it's hard to tell them apart", reporter Oystein Bogen told AFP from the Sochi airport, calling police actions "unusual, disturbing, and systematic" and aimed at preventing the crew from doing their job.

Police in Krasnodar region and nearby Adygea region tailed the reporters' car, singled it out at checkpoints, took them in for questioning, and asked them to disclose their sources, Bogen said, estimating that the total amount of time spent in custody was 11 to 12 hours.

No official reason for such scrutiny was ever presented, he said, but some officers cited "counter-terrorist measures, ordered by the President of Russian Federation".

Rights group Human Rights Watch condemned police actions as "attempts to muzzle media" and said the incidents should "shock" the International Olympic Committee.

"The IOC needs to demand a full explanation from the Russian authorities about the bullying of an Olympic broadcaster's staff," said associate director for Europe and Central Asia Jane Buchanan.

In a report made by Bogen and cameraman Aage Aune, the journalists are shown being stopped at various times of day by officials telling them to turn off their camera, questioned at police stations and even taken to a drug clinic for sobriety tests.

Russia will host the Olympic Games in February in Sochi, its southern resort, an event where thousands of reporters are expected.

Criticism of Olympic development has come from rights activists, environmentalists, and migrant workers who have complained of violations and lack of fair pay.

Bogen said the experience had been useful because he essentially felt himself in the position of local activists who are "exposed to this regularly".

"I never imagined that they would try such a thing against a foreign journalist. Yet it happened, and it remains to be seen if it was a single episode or a tendency that we will see more of before the Olympics," he said.