(Adds detail on Magomedov and his death)
MOSCOW, Feb 6 (Reuters) - Russia said it had shot dead the last surviving militant involved in twin bombings that killed 40 people on the Moscow metro in 2010 during a night-time sweep of a forest hideout in the volatile North Caucasus.
The National Anti-Terrorism Committee (NAK) released a crossed-out photo of the alleged militant on Wednesday, his face framed by a thick beard.
Bombings and attacks on police and officials by Islamist fighters in the North Caucasus are a weekly occurrence, but insurgents have also staged numerous attacks on the Russian heartland.
Chechen Islamist rebel Doku Umarov, Russia's most wanted man and head of the umbrella Caucasus Emirate group, claimed responsibility for the metro bombings as well as a suicide bombing that killed 37 at Moscow's busiest airport in 2011.
"Gusen Magomedov was the last remaining participant directly involved in the organisation and implementation of terrorist attacks on the Moscow metro in March, 2010," NAK said.
"Fair retribution has caught up with the last one of them."
It said Magomedov had been shot after opening fire on security forces combing forests near the village of Kadyrkent in Dagestan, now the centre of militant violence in the North Caucasus.
A video released by NAK showed a mangled body in a black jogging suit and a pistol lying in the underbrush.
An NAK spokesman, Dmitry Pavlov, said Magomedov had personally escorted one of the two female suicide bombers responsible for the twin metro bombings to the entrance of the Moscow underground.
A still image from surveillance footage in the metro published by NAK allegedly shows Magomedov - clean-shaven and wearing a baseball cap - walking beside the suicide bomber.
Later Magomedov, born in 1977, returned to Dagestan and joined a group of insurgents led by a Turkish-born militant, who was killed by security forces last year, Pavlov said.
More than a decade after Moscow re-established federal control over Chechnya following two separatist wars, militants have spread to neighbouring provinces such as Dagestan.
Security risks in the region are in the spotlight ahead of the 2014 Winter Olympics, which Russia will host in the Black Sea resort of Sochi, at the western end of the Caucasus mountains. (Reporting by Gabriela Baczynska and Ludmila Danilova; Writing by Alissa de Carbonnel; Editing by Oliver Holmes and Kevin Liffey)