"What we understand is that Interpol has already issued a 'red notice' for criminal suspect Guo Wengui," foreign ministry spokesman Lu Kang told a regular briefing without giving details.
A red notice is a "request to locate and provisionally arrest an individual pending extradition," according to the Interpol website.
Citing sources briefed on the notice, the South China Morning Post reported Tuesday that Guo is suspected of paying 60 million yuan ($8.72 million) in bribes to disgraced former state security vice-minister Ma Jian, with whom he has been linked.
Guo, who has made allegations of high-level corruption against Communist Party officials, has lived abroad since leaving China two years ago.
"This (red notice) is suicidal behaviour coming from truly corrupt officials who fear that I will expose their crimes," Guo wrote on Twitter Wednesday.
"This will only strengthen my determination to fight these bad guys until the end. Everything is just getting started!"
Using the alias Miles Kwok, Guo noted that Interpol is merely an "organisation, not a government" and that he has not had Chinese identification papers for several years.
Countries are not legally compelled to arrest the subject of a red notice and must decide for themselves how to proceed.
The president of Interpol, Meng Hongwei, was previously China's vice minister of public security -- the first Chinese official to hold the post.
His election last November sparked concern he would give Beijing more leverage to use the agency to track down dissidents abroad.
Guo's tweets this month indicated that he has been in the United States and Britain, neither of which have extradition treaties with China.
In an interview last month with the New York-based Mingjing TV, the billionaire property tycoon described in detail the catalyst for his departure from China: an alleged business dispute with relatives of former top party official He Guoqiang.
He, which has now retired, was the highest-ranked leader in charge of investigating graft within the party's ranks.
Government corruption is rampant in China and President Xi Jinping launched a much-publicised anti-graft campaign after coming to power in 2012.