BEIJING -- PetroChina, China's largest oil and gas producer, recently received notice of complaint from a US court against its former directors and senior management.

On Sept 6 this year, PetroChina confirmed it was facing a lawsuit in the United States.

The complaint, filed with the District Court for the Southern District of New York by an overseas individual shareholder, proposes a class action, PetroChina said on Tuesday evening in a filing with the Shanghai and Hong Kong stock exchanges.

According to the statement, Jiang Jiemin, former PetroChina chairman, Zhou Jiping, PetroChina's current chairman, former CFO Zhou Mingchun and current CFO Yu Yibo were investigated for violations of the securities laws of the United States.

The amount claimed under the complaint is still undeclared. The company will vigorously contest the suit.

Jiang Jiemin has been under investigation for serious disciplinary violations by the Communist Party of China Central Commission for Discipline Inspection since early September this year. Before that, he was head of the State-owned Assets Supervision and Administration Commission of the State Council.