MOSCOW, March 3. /TASS/. A great amount of unverified information on the probe into the recent murder of Russian opposition politician Boris Nemtsov hinders investigation, Russian Investigative Committee spokesman Vladimir Markin said Tuesday on the Rossiya-1 TV channel.

"A great deal of information and disinformation on the crime appears now. The necessary information on the results will only come from us, the official source. All the rest only hinders us," Markin said.

He said "Investigative Committee investigators, Interior Ministry and Federal Security Service operatives are doing everything possible to solve the crime."

"Versions are still the same: this was probably a provocation aimed at destabilizing the political situation in the country," Markin said. "A version linked to an Islamic-extremist trace is also being worked on."

"The possible relation to the Ukrainian events is considered among others. There are radical persons not obeying any authorities among both conflicting sides. But investigators do not rule out versions connected with Nemtsov’s financial activity, personal enmity and a number of other common motives either," he said.

Russian opposition and state figure, deputy of a regional legislature, the Yaroslavl city duma, Nemtsov, was shot dead on downtown Moscow’s Bolshoy Moskvoretsky Bridge overnight to February 28 from a handgun.

Nemtsov was a co-chair of the RPR-Parnas party. He had held a number of government positions in the 1990s. Russia’s Investigative Committee has opened a criminal case into the killing under articles 105 (murder) and 222 (arms trafficking) of the Russian Criminal Code. Investigators do not rule out the murder was a contract killing.

Nemtsov was buried at the Troyekurovskoye Cemetery in Moscow on Tuesday.