The men, who include pro-Western President Mikheil Saakashvili’s personal photographer, have been accused of collecting confidential material on the Georgian leader and sending it to the Russian military intelligence agency.

But the lawyer for the alleged kingpin of the spy ring, European Pressphoto Agency photographer Zurab Kurtsikidze, said the evidence suggested that he was innocent of the charges, which have shocked the local media community.

“The prosecution does not have strong evidence to prove Zurab Kurtsikidze’s guilt,” lawyer Nino Andriashvili told AFP.

Police have released allegedly incriminating video testimony from the president’s photographer and surveillance recordings of phone calls between the suspects discussing payments.

The men have been put under two months’ pre-trial detention and could face up to 12 years in jail if convicted.

Ex-Soviet Georgia fought a war with neighbour Russia in 2008 and has regularly accused Moscow of running espionage operations on its territory.

But Russia on Tuesday branded the latest arrests as a symptom of “paranoia”.

“Anti-Russian hysteria in Tbilisi is gathering steam once again,” Russian foreign ministry spokesman Alexander Lukashevich said in a statement.

“The (Georgian) authorities are working hard to convince the international community and their own public that Georgia is swimming with spies and saboteurs,” he said.

Around 100 journalists and rights campaigners gathered outside parliament on Tuesday in the latest of a series of rallies to demand that the case, which has been classified as secret, be opened up to public scrutiny.

“The evidence which has been released is not convincing, that is why society and the media community is disturbed,” journalist Zviad Koridze told AFP at the rally.

The authorities say the men were detained for passing on documents clearly marked as secret, not because of their journalistic work.

“We must emphasise that the detention of the photographers has nothing to do with freedom of the media and the restriction of media activities,” Saakashvili’s spokeswoman Manana Manjgaladze said at a news conference.

However another of the suspects, foreign ministry photographer Giorgi Abdaladze, has claimed that they were targeted because they photographed protesters beaten by riot police at a rally in May and sold the “shocking” pictures to international media.

The interior ministry has described the claim as “ridiculous”.

The German ambassador to Tbilisi visited the ministry after the Frankfurt-based European Pressphoto Agency complained strongly about the arrest of its photographer Kurtsikidze.

Ambassador Ortwin Hennig asked the ministry “to ensure that the trial will be fair and transparent”, local media reported an embassy spokeswoman as saying.

The United States, Georgia’s main Western supporter, has also called for transparency.

“You know we believe in freedom of the media; but if, in fact, there have been actions incompatible with that, then we would want to see a transparent and accountable judicial process,” US State Department spokeswoman Victoria Nuland said at a briefing on Monday.