Copies of a book linking Russia's FSB security service to apartment blasts in 1999 have been seized by the Russian police, the book's sellers say.
Litvinenko (on screen) fled to Britain in 2000
Over 4,000 issues of FSB Blows Up Russia were confiscated in western Russia on Sunday, Alexander Podrabinek of the Prima news agency said.
Mr Podrabinek said "the books were seized as anti-government propaganda".
The FSB denies any involvement in the blasts that killed nearly 300 people and led to the second war in Chechnya.
Instead, it has blamed Chechen rebels for organising the September 1999 bombings - two in Moscow and two in Volgodonsk.
On Tuesday, the FSB's press office said it had no information about Sunday's incident, according to the Associated Press news agency.
Dissident FSB agent
The copies of the book were seized en route from the western city of Pskov to Moscow after being stopped by road police, Mr Podrabinek said.
Russia sent it troops to Chechnya within weeks after the blasts
He said Prima ordered the books - which were printed in Latvia - for sale in Russia, adding that it was a legal transaction "observing all customs formalities".
The book is co-authored by former FSB agent Alexander Litvinenko, who fled to Britain in 2000 and was given political asylum there.
Mr Litvinenko has accused his superiors of carrying out the apartment bombings and also of ordering him to kill Russia's exiled tycoon Boris Berezovsky.
Last year, Mr Litvinenko was tried in absentia by a Russian court and sentenced to three-and-a-half-years in prison sentence for abuse of office and stealing explosives.
The sentence was suspended.