China and the United States are in "advanced negotiations" on returning to China five of its most wanted corruption suspects who have fled to the United States, a state-run newspaper said on Wednesday.

China has vowed to pursue an overseas search, dubbed "Operation Fox Hunt," for corrupt officials and business executives who have fled abroad and for their assets, part of President Xi Jinping's war on deep-seated corruption.

It has been pushing for extradition treaties, but Western countries have been reluctant to help, not wanting to send people to a country where rights groups say mistreatment of suspects is a concern.