Pro-democracy campaigner Professor Joseph Cheng Yu-shek has hit out against what he says is a smear campaign by pro-Beijing media that is intended to threaten Hong Kong's core values. The City University scholar was making an official response yesterday to accusations that he falsely stated his nationality when applying for a Hong Kong passport in 2002 and took credit for others' work in academic papers published more than a decade ago. The allegations occupied the full front page of pro-Beijing daily Wen Wei Po for three days and were heavily reported by other pro-establishment newspapers. "These are just private matters," said Cheng, who is also the convenor of the Alliance for True Democracy. "How is it worth front-page coverage on a newspaper for days? I believe it's a smear campaign trying to hurt the alliance." Cheng also questioned how the newspaper had obtained confidential government information about a "mistake" in his passport application. Wen Wei Po said it had been told that Cheng, his wife and their two children obtained Australian nationality in the early 1990s and that he gave up Chinese citizenship in 1997. The newspaper said it was told Cheng wrote "Chinese" as his nationality when filling in the application form for a Hong Kong passport in 2002 and the Immigration Department rejected it after finding out the statement was false. Cheng said he got the nationality wrong "by mistake" and had corrected it when asked by the Immigration Department. He said only his family, his lawyer and government officials knew details of the application. "Where did Wen Wei Po get such confidential government information dating back 12 years?" he asked. "I deeply regret that I've been smeared and personally attacked by pro-Beijing media for days because of our demand for democracy. This is a serious threat to Hong Kong's core values." Regarding the accusation of taking credit for others' work, Cheng said that in a paper resulting from a joint project with a mainland university professor, his assistant had failed to list the professor's name as co-author. He said reference to "the authors" had appeared in the article at least three times, indicating he had no intention to take the other professor's credit. He had contacted the professor personally and through a mutual friend to apologise, he added. The mainland professor could not be reached last night.