Beijing on Thursday denied rejecting a New York Times reporter's visa after the paper -- which has published a series of exposes on Premier Wen Jiabao's family -- said he had been forced to leave mainland China.

Chris Buckley, a longstanding China correspondent recently employed by the Times, departed Beijing for Hong Kong on Monday after the authorities did not issue him a working visa for 2013 before the year's end, the newspaper said.

"There has not been any so-called rejection," an official from the spokesman's office of the ministry of foreign affairs told AFP in response to faxed questions about Buckley.

His visa application was still being processed, she said, adding that at present it "did not meet all requirements, but has not been delayed".

The official declined to give her name and also refused to specify which requirements had not been fulfilled, adding that Buckley "should be clear about that himself".

The Foreign Correspondents' Club of China, which represents foreign journalists in the country, said Thursday it "strongly regrets" what it called "delays" in Buckley's accreditation.

In a statement it linked the apparent delay to a Times investigation into the huge riches amassed by the family of Wen, who is soon to step down as premier.

The New York Times in October published reports saying that relatives of Wen have controlled assets worth at least $2.7 billion during his tenure.

Lack of clarity over Buckley's accreditation "inevitably raises suspicions that the authorities are punishing the New York Times" for the articles, the statement said.

Buckley, who has worked as a reporter in China for 12 years, was previously employed as a correspondent for Britain-based news wire Reuters, and rejoined the New York Times in October.

It is the latest instance of what press groups say is a series of cases in which Chinese authorities have obstructed the work of foreign journalists, who sometimes have a difficult relationship with Beijing.

David Barboza, the New York Times' Shanghai bureau chief who wrote the Wen articles, was among six other Times correspondents in China who had their visas renewed.