WASHINGTON, Jan 14 (Reuters) - The United States said on Monday the arrest in China of prominent AIDS activist and human rights campaigner Hu Jia was "disturbing" and Washington had raised his case with the authorities in Beijing.

State Department spokesman Sean McCormack said Washington was closely following the arrest of Hu, 34, who was taken into custody at the end of last month.

Police in China have also prevented Hu's wife, fellow activist Zeng Jinyan, their newborn baby and Zeng's elderly mother from leaving the couple's Beijing home.

"This is a case that we have been following closely, and we've brought it up with Chinese authorities. It's disturbing," McCormack told reporters.

"I would expect that the Chinese government would want to provide some details about this case. It's one that is important and that our embassy in Beijing is following quite closely," he added.

Named by Time magazine as one of the world's 100 most influential people, Hu first came to prominence over his advocacy for AIDS sufferers in rural China.

Deputy Secretary of State John Negroponte is visiting China this week and U.S-based human rights groups urged him to raise Hu's case personally with the authorities.

The AIDS Policy Project, a human rights and AIDS organization, demanded the immediate and unconditional release of Hu, access to his lawyer as well as the release from house arrest of his wife and family.

"Chinese New Year is coming up. He shouldn't be in jail for his family's first holiday with the baby," said the group in a statement. (Reporting by Sue Pleming, editing by Cynthia Osterman)

AlertNet news is provided by