Hong Kong’s anti-corruption watchdog has launched an investigation into Donald Tsang, the territory’s chief executive, following allegations that he received inappropriate favours from local business tycoons such as overseas trips on private jets, staying on luxury yachts and leasing an apartment for below market price.

Mr Tsang said that he had never acted against the law nor breached internal rules, and that he would fully co-operate with any investigation if contacted by the Independent Commission Against Corruption.

Avery Ng, vice-chairman of the League of Social Democrats, a pro-democracy party, said: “The ICAC has informed us that they are looking into the trips and the leasing of the apartment after we lodged a complaint against Mr Tsang.” The ICAC refused to comment.