Russia's President Vladimir Putin.

Moscow -

Russian investigators on Friday searched the home of a film-maker who is working on a documentary about the protest movement, leading a news anchor to complain to Prime Minister Dmitry Medvedev of pressure in a live interview.

Acclaimed cinematographer Pavel Kostomarov is directing The Term (Srok), which chronicles Russia's political life after Vladimir Putin was sworn in for his third Kremlin term in May.

His colleague Alexei Pivovarov, a star news reader on state-controlled NTV channel, denounced the early morning raid during a live interview with Medvedev, calling it an affront to all journalists.

“How are we to work, Dmitry Anatolyevich, if we are subjected to raids?”, Pivovarov asked Medvedev, saying police arrived at Kostomarov's apartment without a warning early Friday.

“They could have just asked for video materials, but to arrive at 7 am (0300 GMT) for a search...,” he told Medvedev.

Investigators earlier confirmed to Russian news agencies that the raid occurred because Kostomarov is a witness in a probe into unrest Russian authorities have launched after a violent protest on May 6, which he was filming.

He has also been summoned for questioning.

“I guess they had their reasons,” Medvedev answered. “If your colleague believes his rights have been violated he can file a complaint, that is normal.”

Medvedev was speaking during his annual interview to Russia's top television channels Friday.

Kostomarov is best known for his award-winning camerawork in the Arctic-set drama How I Ended This Summer.

In May, he launched The Term as co-director, together with Pivovarov and documentary-maker Alexander Rastorguev. He also films for the project, along with a dozen other video journalists who travel across Russia.

The first segment they published on their video blog showed the arrest of protest leaders at the May 6 protest, with riot police grabbing anti-corruption blogger Alexei Navalny and twisting his arm as he cries out in pain.

Since then they have posted small clips of rallies and trials on a near-daily basis. They have also featured in-depth, personal interviews with opposition leaders.

The probe into the May 6 disturbances, when protesters clashed with riot police after being forced into a bottleneck which caused a crush, has already seen 17 people charged.

One man has been convicted and jailed for four-and-a-half years for shoving and throwing pieces of asphalt at several police officers.

The case has been decried by the opposition as disproportionate prosecution of random activists, where many suspects are spending many months in pre-trial jail, while policemen are rewarded with apartments.

Medvedev however defended the probe Friday, saying “anyone who goes to a rally and thinks he can hit a policeman should understand that he will be held accountable.”

“You cannot hit policemen,” Medvedev said. “That is the basis of law and order in any society.” - Sapa-AFP