Russian authorities have reportedly arrested, tried and repatriated a North Korean worker who was preparing to defect from a labour camp in the Russian Far East, with human rights activists suggesting Moscow has started to cooperate with Pyongyang in its crackdown on defectors.

The worker - identified as 29-year-old Jun Kyung-chul - had served as a private in the North Korean People’s Army before being sent to work in Russia about one year ago, the Daily NK, a Seoul-based dissident news site, reported. Unhappy at the gruelling work conditions, he had made plans to defect to South Korea before being caught.

The reports claim he had been receiving assistance in his bid for freedom, but disappeared in early November.

An unnamed source told the Daily NK that North Korean authorities requested the assistance of Russia in detaining Mr Jun, who was put on trial in the city of Vladivostok on November 7, although the charges he faced have not been verified. Russia and North Korea have agreed in the past to extradite anyone found guilty of a crime in each other’s territory.

Mr Jun was convicted, handed over to the custody of representatives of the Pyongyang government and transferred over the border to North Korea the same day.