China's 'most wanted' economic fugitive Yang Xiuzhu has reportedly given up her application for political asylum in the United States and plans to return to China as soon as possible.

Speaking on her behalf, Yang's lawyer Vlad Kuzmin said as medical provision in US jails was poor and her application for asylum had been postponed for eight months, Yang hoped to return to China to gain access to better medical treatment.

Kuzmin said Yang could return as soon as this August.

The 70-year-old former vice mayor of Wenzhou in east China's Zhejiang Province has been on the run for 12 years, and entered the US in 2014.

Yang is currently being held on immigration charges in the US.

Chinese investigators have accused Yang of accepting bribes worth more than 250 million yuan or 41 million US dollars while in office, putting her top of the Chinese government list for corrupt officials who have fled abroad.

Officials such as Yang have become an increasing focus of Chinese President Xi Jinping's anti-corruption campaign since last year, after it expanded overseas with its "Sky Net" and "Fox Hunt" programs aimed at catching runaway corrupt Party members.

From April to December last year, China seized 857 fugitives hiding overseas, scattered across 66 countries and regions in the "Fox Hunt 2015" campaign.