Local authorities say the building was closed due to its state of disrepair but this is rejected by the museum's director, who claims his work had angered officials.
A Russian museum dedicated to the Gulag has been forced to close, its director has confirmed, in the latest case of authorities putting pressure on those researching the Soviet-era camps.
Nikolai Arakcheyev, director of the institute in Yoshkar-Ola, western Russia, said on Friday they no longer have access to the museum and there had been "an attempt to seize the exhibits, probably at the request of the town hall".
A source in the local culture ministry said that the building had been closed because it was in a state of disrepair and was "a danger to visitors".
The ministry was not immediately able to provide a comment.
But Mr Arakcheyev, a former soldier, rejected the idea the building was dangerous and said only the roof needed repairs.
He has worked in the local branch of the NGO Memorial, which specialises in human rights and Soviet-era repression, for several years.
'A source of historical truth and freedom'
For decades he has been trying to find and catalogue the remains of victims of Stalinist repressions in nearby forests, where they were shot in the hundreds.
Mr Arakcheyev said his activities angered local authorities.
"They want to destroy the museum, which is a source of historical truth and freedom," he said.
This month, Yury Dmitriyev, a respected Russian historian who has also researched Stalin-era mass graves, was charged with sexual assault following an earlier acquittal on similar charges.
He faces up to 20 years in prison if convicted.
In June, a Russian researcher said he had discovered Moscow ordered the destruction of prison records including some relating to the Soviet Gulag, after he submitted a request for archive material.
Under President Vladimir Putin, Russian authorities have moved to downplay the horrors of Soviet imprisonment of millions, including political dissidents in prison camps.