Beijing, July 17 (DPA) China has sentenced a well-known environmental activist and his daughter to 'reform through labour' after accusing them of 'endangering state security' by disclosing details of radioactive pollution from a uranium mine, rights groups said Friday.

Sun Xiaodi, a former employee of the state-run Number 792 Uranium Mine in the northwestern province of Gansu, has campaigned for more than a decade to draw attention to pollution from the mine.

Public security officials in Gansu last week ordered that Sun, 53, serve two years at a labour camp, claiming he had been 'illegally providing state secrets overseas' and was guilty of 'rumour mongering', US-based Human Rights in China and other groups said.

His daughter Sun Haiyan, 25, was sentenced to 18 months of reform through labour for helping him, the reports said.

Reform-through-labour (RTL) sentences are passed by local judicial committees without trial.