By Steve Rosenberg BBC correspondent in Moscow

A new series of Russian stamps is causing controversy for carrying the portraits of six of Stalin's secret policemen.

Stalin's henchman carried out horrific atrocities

They have raised concern among human rights groups that the power and influence of the country's secret services may be growing.

Anyone receiving a letter in the Russian post is likely to be a little unnerved by the faces staring up at them from the envelope.

They are a rather unlikely group of celebrities. They include:

• Sergei Puzitsky, responsible for the deportation of thousands of peasants during the 1930s
• Vladimir Styrne, a man said to have instigated widespread repression when he was in charge of a local branch of the secret police

The six agents are better known in Russia for their success in catching foreign spies, and it is in that capacity they are being honoured by the country's postal service.

The stamps have been issued to mark the 80th anniversary of Russia's counter-intelligence service.

"We're starting to realise in Russia that not everything in our history was bad. These were honest, decent citizens. Some of them were even geniuses. They helped protect our country and our people," said Boris Mitukin, chief designer at the Russian House of Stamps.

Soviet habits

Not everyone, though, is celebrating.

Human rights activists have expressed their opposition to the idea of putting spies on stamps.

Can you imagine modern Germany putting members of the Gestapo on their stamps?

Susanna Pechora

"It's clear that [President Putin] and his colleagues from ex-Soviet KGB, have now become very powerful persons and they have old Soviet ideological habits, to find the heroes among the members of the secret police," said Nikita Petrov, a researcher for Memorial, an organisation dedicated to the victims of Stalin's terror.

Susanna Pechora, who spent five years in the Gulag, has little sympathy for the new heroes of the Russian postal system.

"There's no way I'd put one of those stamps on one of my letters. That would be an insult. Can you imagine modern Germany putting members of the Gestapo on their stamps?" she said.

"It's a slap in the face to the millions who died in that totalitarian system. It's just awful that we live in a society where hangmen and murderers are glorified".