Alexeyev, who went missing on Wednesday amid conflicting reports, told the Echo of Moscow radio station that he had been detained at a Moscow airport and taken away by officials who “had no police uniform and did not give any names”.

He told the radio station that officials had asked him to withdraw complaints that he submitted to the Strasbourg-based court over Moscow Mayor Yury Luzhkov’s refusal to allow gay pride marches.

“They only talked about Moscow Pride and the complaint to the European court,” Alexeyev said, adding that he was asked to sign a paper withdrawing his complaint.

“They even offered me a concrete paper so that I could sign it. Naturally I did not sign any papers. I absolutely definitely state that I did not withdraw any cases from the European court.”

His captors eventually released him and he discovered that he had been held in the town of Tula, around 180 kilometres (110 miles) from Moscow, said Alexeyev, who posted a message on his blog early Saturday announcing his return.

Luzhkov has repeatedly banned gay rights parades in Moscow, calling them “satanic”, and riot police have roughly broken up unsanctioned protests by Alexeyev and international gay rights activists.

The cases filed to Strasbourg by Alexeyev “are in a final stage, that is a court decision is inevitable by the end of the year”, he told Echo of Moscow.

Luzhkov is fighting for his political future after criticism from the Kremlin over his handling of a smog and wildfire crisis in August. He has been the subject of a series of mud-raking documentaries on national television.