A Russian nuclear scientist has been charged with disclosing state secrets and faces up to four years in prison over an article he published in a Czech journal, his lawyer said Wednesday.

Vladimir Golubev, a former employee of the country's top nuclear weapons research and development centre, is accused by the security services of disclosing state secrets after publishing an article about explosives in a Czech journal, his lawyer told AFP.

The article was based on a report he gave at an international conference in the Czech Republic in 2013.

Last summer the FSB security service, the successor to the Soviet-era KGB agency, raided the scientist's apartment in the central Russian city of Nizhny Novgorod and opened a criminal case against him, his lawyer Yevgeny Gubin told AFP.

The scientist, who is under pledge not to leave the city and is not allowed to speak to media, denies having committed a crime. He insists the information he published in the Czech journal is available to the general public, said Gubin.

"He contacted me yesterday," Gubin said, adding that the scientist's interests had been previously represented by a state-appointed lawyer. "I am now studying the case."

Golubev worked at the Russian Federal Nuclear Centre located some 500 kilometres (300 miles) southeast of Moscow between 1975 and 2013.

The centre designed the Soviet Union's first nuclear bomb and is considered to be the Russian equivalent of the United States' Los Alamos facility.

The FSB declined immediate comment.

Golubev is the latest Russian scientist to be charged with disclosing state secrets or spying.

His lawyer said his prosecution appeared to reflect a "general trend."

"Spies are everywhere," he said, referring to what he described as the security service's apparent logic.

The Public Committee for Protection of Scientists pledged to oversee Golubev's case on Wednesday.

"We already have some 20 people who have been jailed over nothing," a member of the committee, Yury Ryzhov, said on radio.

In 2004, Igor Sutyagin, a Russian arms control expert, was convicted of handing over classified information to a British company that Russia claimed was a CIA cover, and sentenced to 15 years in jail.

He pleaded not guilty, saying the information came from open sources and was not a state secret.

In 2010, Sutyagin was deported to Britain as part of a spy swap with the United States.

Last month, a mother of seven was accused of treason for calling the Ukrainian embassy with information on possible Russian troop movements. She faces up to 20 years in prison.