A 10-year-old boy who lost both parents in the March 29 Moscow metro bombings sued federal authorities for 5 million rubles ($170,000) on Tuesday.
The boy is among several relatives of the 40 people killed in the twin bombings who filed a lawsuit against the Finance Ministry, which oversees state spending, and the National Anti-Terrorist Committee for not preventing the attacks, their lawyer, Igor Trunov, told Interfax.
Trunov did not provide additional details about the boy.
Trunov, who also has represented victims of previous terrorist attacks, voiced doubt that Russian courts would award damages in the lawsuit and promised to appeal to the European Court of Human Rights if necessary.
Russian law permits victims of terrorist attacks to only sue terrorists, not authorities, for compensation. But Trunov pointed to a number of decisions by the European court in which the Russian government has been held responsible for the well-being of its citizens.
North Caucasus Islamist rebels have claimed responsibility for the metro bombings, which injured more than 90 people.
The government has promised to pay 1 million rubles ($33,000) to families of every victim of the blasts.
Meanwhile, investigators may have found a Moscow region apartment where the suicide bombers stayed before the attack, Interfax reported Tuesday, citing a police source.
The apartment in the town of Odintsovo was rented by Akhmed Rabadanov, suspected of being the guide and supervisor of the female attackers, the report said.
Rabadanov was killed in Dagestan in a police operation April 26, it said.
Investigators tracked some of Rabadanov's mobile phone calls to Odintsovo, where residents of one of the apartment buildings recognized his photo.
About 1 kilogram of explosives was found in the rented apartment.