BEIJING - Thousands of officials have fled China over the past 30 years with some 50 billion US dollars in public funds, state media said Monday, as the government scrambles to stem the tide of corruption.

As many as 4,000 officials have disappeared, using criminal gangs, mainly in the United States and Australia, to launder their ill-gotten gains, buy real estate and set up false identities, the Global Times said.

A joint task force involving 15 Chinese ministries has been set up to choke off graft in government ranks, the paper said.

In 2009, authorities investigated 103 cases involving the outbound travel of more than 300 officials, the paper said, citing a party official tasked with disciplinary issues.

In one case, the disappearance to France in 2008 of Yang Xianghong, a top Communist Party official in Wenzhou city, led to the arrest of his wife, who was charged with trying to launder 20 million yuan (S$4 million), it said.

The paper did not detail how the 50 billion US dollars were funneled overseas, or how the officials were linking up with criminal gangs abroad.

Chinese President Hu Jintao has for years made fighting official corruption a priority, saying that the scourge is a matter of life and death for the ruling Communist Party.

In recent years, China has sought to negotiate more extradition treaties with Western nations to help it repatriate and punish officials fleeing overseas with public funds.