MOSCOW, August 19. /TASS/. Zhanna Nemtsova, the daughter of murdered Russian opposition politician, has challenged the refusal of the Russian Investigative Committee to interrogate Chechen leader Ramzan Kadyrov in connection with the case, her lawyer has told TASS.

Lawyer Vadim Prokhorov said he filed a complaint earlier on Wednesday asking the Russian court to rule that the refusal of an investigator to question Kadyrov and four other Chechen officials over the murder of Boris Nemtsov is "illegal and unfounded."

"We also ask the court to declare illegal the inaction of the Russian Investigative Committee officials who have distanced themselves from finding the contractors and organizers of the murder," the lawyer said.

A spokesperson for the Moscow-based Basmanny court, Anna Fadeyeva, said the court has received the complaint that will be considered in line with the established procedure.

The complaint says that Kadyrov personally knew the suspects in the Nemtsov murder case, Zaur Dadayev and also Beslan Shavanov, who blew himself up during the detention in Grozny.

The plaintiff says "taking into consideration the statements of Kadyrov and also the old-time history of his conflict with Nemtsov, the head of Chechnya may have information not only on the perpetrators of the murder, but also on the organizers and contractors."

The complaint says Nemtsov’s long-time aide and press secretary Olga Tikhomirova and journalist Alexander Ryklin who knew about the threats against Nemtsov from Kadyrov have already given their testimony.

The daughter of the murdered politician and her lawyer say all this constitutes grounds for the interrogation of a number of high-ranking Chechen officials as witnesses as part of the criminal case.

The lawyer said earlier a petition had been sent to the Investigative Committee for the interrogation of six people, which was met mostly with refusal. The investigators however satisfied a motion to question another Chechen citizen, Ruslan Geremeyev, whose whereabouts are still unknown.

Co-chairman of the Parnas opposition party Boris Nemtsov was shot dead in downtown Moscow on February 27. Zaur Dadaev whom investigators consider the killer, Khamzat Bakhaev, Anzor Gubashev, Shadid Gubashev and Tamerlan Eskerkhanov have been arrested over Nemtsov’s murder.

Earlier this month, the Russian Investigative Committee extended the investigation of Nemtsov’s murder till November 28.