A prominent Chinese businesswoman has come under fire after she was exposed as having a foreign passport, highlighting resentment towards the rising number of wealthy emigrants.

There were calls for a boycott of South Beauty, one of the country's best-known restaurant chains, after its founder Zhang Lan obtained a second nationality, the state-run China Daily reported Tuesday.

It did not say which country issued the new passport.

Beijing does not allow dual citizenship and those who take a second nationality lose their right to a Chinese passport.

The case reflects a growing willingness by wealthy Chinese to seek foreign citizenship, with nearly half the country's richest people considering emigrating, according to a report last year.

The survey by the Bank of China and the Hurun Report found that 46 percent of Chinese with assets worth more than 10 million yuan ($1.6 million) were considering moving abroad, while 14 percent had already begun the process.

The most popular destinations were the United States and Canada. Respondents cited a rigid education system, pollution, rising living costs and widespread corruption as their main motives for emigration.

Many wealthy Chinese can take advantage of "investment immigration" policies offered by other countries, which offer citizenship in return for property purchases or bank deposits.

Zhang is a member of the Chinese People's Political Consultative Conference, a body which functions as a rubber stamp for decisions by the ruling Communist Party, and which had previously accused emigrants of taking wealth out of China.

"I will be loyal to my country because I'm a Chinese," the China Daily quoted her as saying in a television interview.

Her foreign passport was exposed by a Beijing court handling a lawsuit she was involved in, the paper said. It said a member of the National People's Congress, China's parliament, had called for a boycott of her restaurants.

Users of Sina Weibo, a website similar to Twitter, expressed cynicism at Zhang's decision.

"Our politicians all send their children abroad to study, and so many corrupt officials emigrate... There's nothing fresh about this case," one user wrote.