BEIJING (AP).- Famed Chinese artist Ai Weiwei, who disappeared earlier this month and is believed to be in police custody, is being investigated for allegedly evading his taxes and destroying evidence, a Hong Kong newspaper reported Thursday.

The Beijing-backed Wen Wei Po newspaper quoted unnamed sources as saying Ai, an outspoken government critic, is suspected of evading large amounts of tax, though no exact figure was given, and destroying papers that might have been used as evidence against him.

His family denied the paper's claims and said the government is trying to punish him for his social activism.

"He has made the government unhappy by speaking up for ordinary people," Ai's sister Gao Ge told The Associated Press. "Now the government wants to get him back."

The Wen Wei Po is often used by the Beijing government to help shape public opinion among Chinese in Hong Kong, which has a vibrant, free media. The report is of a piece with several recent editorials in mainland newspapers attacking Ai.

It said he was also being investigated for bigamy because he has a young son with a woman other than his wife and is suspected of spreading pornography online.

Before he disappeared, Ai had been keeping an informal tally of the recent detentions of activists, lawyers and writers on Twitter. China has stepped up those detentions since February when online calls for protests similar to those in the Middle East and North Africa began to circulate.

Ai has also spoken critically about a number of national scandals, including the deaths of students in shoddily built schools that collapsed during the 2008 Sichuan earthquake, children killed or sickened by melamine-tainted infant formula and a deadly high-rise fire in Shanghai that killed 58 and was blamed on negligent workers and corrupt inspectors.

Gao called the newspaper report "comical" and said the allegations indicated that police have no substantial evidence against her brother.

Ai's wife, Lu Qing, said that the company that handles Ai's financial affairs, Beijing Fake Cultural Development Ltd., is registered under her name and belongs to her.

"So why do they accuse him of tax evasion?" she asked. "Authorities are clearly acting in bad faith."

Lu said the bigamy claims were fabricated and that her husband has only married once.

"Whatever else happened in his life is our private matter," she said.

Ai and Lu married in the United States but haven't registered the union in China, Gao said. He has a child with another woman but the arrangement is open and amicable, she said.

"There is no accuser," Gao said. "Everyone is fine with the situation as it is."

Gao said the suggestion that Ai posted pornography online probably refers to a seminude self-portrait he put on the Internet.

In the photo, Ai's groin is obscured by a plush toy animal. The animal — a grass mud horse — is fictional. It was invented by Chinese Web users to slyly insult the nation's Internet censors because the Chinese characters of the name are homonyms for a graphic slur.

"It's art and so it should be reviewed by the art community, not ordinary people," Gao said. "My mother doesn't like it either, but she accepts it."

The Wen Wei Po said Ai was cooperating with authorities after initially refusing to do so when he was first taken into custody on April 3.

The Chinese Foreign Ministry earlier confirmed Ai was suspected of economic crimes. Asked about the Wen Wei Po report at a news briefing Thursday, Foreign Ministry spokesman Hong Lei referred reporters to the "relevant authorities."

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Associated Press writer Alexa Olesen in Beijing contributed to this report.


Copyright 2011 The Associated Press.