A Hong Kong-based human rights group says that authorities in the eastern Chinese city of Hangzhou have detained at least three members of the China Democracy Party on grounds of subversion.

The Information Centre for Human Rights and Democratic Movement in China says the arrests come on the eve of the expected trial on subversion charges of another four members of the party in Hangzhou.

The group says a CDP member Tao Haidong from Xinjiang region was also detained after meeting party members in the northern Province of Shaanxi.

There's been no independent confirmation of the detentions.