Russian Federal Security Service (FSB) announced Wednesday that they have seized an archive belonging to an insurgent recently killed in Dagestan, who was believed to have masterminded bombings of Moscow subway in March.

FSB head Alexander Bortnikov said those papers would help find more terrorists, local media reported.

The killed insurgent Magomedali Vagabov was husband of one of the two female suicide bombers. He and four other rebels were killed in Gunib town of Dagestan last Saturday during an anti- terrorist special operation.

Also on Wednesday, head of the Investigative Committee of Prosecutor General’s Office, Alexander Bastrykin, confirmed that Vagabov’s group plotted the subway bombings that claimed 40 lives and injured 90 others.

“He got what he deserved,” Bastrykin told the official Rossiiskaya Gazeta daily in an interview that will be published Thursday.

Bastrykin also said that several more insurgents killed in recent months were members of Vagabov’s group. One of the gang members blew up himself in Dagestani town of Kizlyar in late April.

Two female suicide bombers aged 28 and 18 were dispatched to Moscow from Dagestan by members of Vagabov’s group, Bastrykin said.