The report cited a Commerce Ministry report of last year that said 4,000 officials have escaped the country in recent years and taken five billion yuan (HK$4.80 billion) in embezzled funds with them, giving China the world's fourth-most serious problem with capital flight.

``It is very difficult to get corrupt officials back from their main `destination countries,' such as the United States, Japan and Canada, because China has not signed extradition treaties with those nations,'' Chu Huaizhi, a law professor at Beijing University, was quoted as saying.

One of China's most wanted fugitives, accused smuggling kingpin Lai Changxing, has been able to stay in Canada since fleeing there in 1999.

The Canadian government has said it supports China's bid to have Lai returned to face charges, but he has avoided that so far as the case moves slowly through Canadian courts.

Corruption, virtually wiped out in China in the years after the communists came to power in 1949, has roared back in the wake of economic reforms introduced in the late 1970s.

Many of those living abroad and accused of corruption were bank officials or managers of state-owned enterprises.

Chu said China's use of the death penalty for non-violent crimes makes the extradition process even more difficult, because many countries refuse to send back foreign nationals who could face possible execution.

Canada traditionally is one such country. Beijing has pledged Lai Changxing will not be executed if he is returned and found guilty, but Lai argues Beijing will simply ignore its promise if he is extradited.

For years, some Chinese legal experts have called for limits on death sentences in non-violent cases, Chu said, adding if corrupt officials were not afraid of facing execution, many of them would not choose to flee the country.

``But Chinese people's cries for severe punishment of corrupt officials are very loud and you have to consider the country's needs to stem graft. A decision on whether or not to keep imposing the death penalty for non-violent crimes will require further debate and experiments,'' Chu said.

Rights groups say China executes 5,000 to 12,000 people every year - more than any other country.

The government in July asked courts to think twice before handing down the death penalty, though Premier Wen Jiabao said earlier in the year that ``national conditions'' would not allow China to abolish executions.

Last August, Beijing passed a new regulation requiring senior officials to check in with superiors before leaving the country in an attempt to stem the tide of massive graft.