PetroChina’s supplier Wison Engineering Services Co Ltd and its chairman Hua Bangsong have both been found guilty of paying bribes, the company said in a Hong Kong stock exchange filing.

A Chinese court has ordered Wison to pay a fine of 30 million yuan ($4.83 million) and sentenced the chairman to 36 months in jail on the same charge. They were both acquitted of conspiracy to commit a tender-offer fraud. The company said it was reviewing the judgment to decide whether to appeal.

Hua, the controlling shareholder of Wison, was reportedly implicated in the high-profile corruption scandal of China National Petroleum Corp. and its listed unit PetroChina, which had brought down dozens of oil executives and tycoons.

Chinese prosecutors filed charges against Wison and Hua in November last year, accusing them of offering unlawful advantages, including a property valued at 7.62 million yuan ($1.2 million), to a senior manager of an unnamed customer in 2009. They were also charged with fraud relating to an irregular tender for a project in 2004.

Wison has allegedly won numerous contracts from Petrochina. Hua was rumored to be holding  Wison’s shares on behalf of Zhou Bin, the son of jailed former security chief Zhou Yongkang. The elder Zhou who previously controlled China’s lucrative oil sector with his allies has been sentenced to life in prison for bribery and leaking state secrets.

Wison denied Hua’s alleged connections with the Zhou family in an earlier filing.

Sources: Ifeng (凤凰财经), Reuters