A group of Irish polar circumnavigators held a silent vigil today outside the Russian Embassy in Dublin in protest over the imprisonment of Russian historian Yuri Dmitriev.

As Afloat reported earlier this week, the crew of yacht Northabout, which successfully transited the North-West and North-East passages, met Dmitriev on their navigation of the White Sea/Baltic canal in 2012.

Dmitriev, a Gulag researcher, historian and human rights activist, has dedicated most of his life to documenting burial sites of those who died during Soviet-era repression.

Grandfathers for Human Rights - the polar sailor protest at the Russian Embassy in Dublin Photo: Gary Finnegan

Northabout skipper Jarlath Cunnane, Colm Brogan and and pilot on the White Sea Canal in 2012

Last December, a Russian court added two more years to a 13-year jail sentence imposed on Dmitriev after he was found guilty of sexually abusing his adopted daughter – a charge he has denied.

Supporters of Dmitriev say the charges were fabricated to punish him for uncovering mass graves of Stalin's gulags.

Dmitriev worked with prominent rights group Memorial on documenting Soviet-era repression.

Historian and human rights activist Yuri Dmitriev and his daughter on board Northabout in 2012

During the 1937-1938 Great Terror, at least 700,000 people were executed according to officials. Dmitriev located a mass grave containing thousands of bodies of people held in the Gulags, the Soviet prison camp network.

Mass graves shown to the crew of Northabout during their 2012 transit of the White Sea canal

The crew of Northabout include sailor and boatbuilder Jarlath Cunnane, Dr Michael Brogan, Paddy Barry, Gary Finnegan, Colm Brogan and Kevin Cronin.

They held their one-hour vigil outside the Russian embassy in Dublin on Wednesday, February 9th, and were supported by Irish members of the human rights group PEN-International.

Dr Michael Brogan (from left), historian Yuri Dmitriev and Colm Brogan during Northabout's transit of the White Sea canal in 2012

They said they met up with Yuri Dmitriev in the city of Petrozavodsk, on the shores of Lake Onega, during their White Sea canal voyage.

“He took us to Sandarmokh forest and other burial sites around the area, where we met relatives of some of the victims,” they said.

“Dmitriev is trying to ensure that Russia remembers its past, and the importance of truth to prevent new atrocities,” they said.

“He has paid a high price for highlighting Stalin’s reign of terror, which Mr Putin wants to whitewash from Russian history,” they said.

A memorial to those who died at Sandarmokh forest on the White Sea canal route

The group has also criticised a Russian Supreme Court decision to close Memorial, the country's most prominent human rights group, which chronicled Stalin-era purges.

“This same court has refused to review Dmitriev's case which, at close to 66 years of age amounts almost to a death sentence,” they said.

“While the present administration is once again setting out to erase the memory of the victims as if they never existed, the future looks grim for anyone who might speak up for the truth of Russia's dark history,” they said.

Thousands of workers are believed to have died during the construction of the 227 km-long White Sea Canal, which was built in 20 months between November 1931 and July 1933.

The sailors recall that Dmitriev examined the records of one field hospital alone along the canal route, and documented the deaths of 10,000 prisoners working on the eighth lock in the winter of 1932.