Updated

Michael Jackson has been hospitalized in Las Vegas with pneumonia, sources tell FOXNews.com's 411 column.

During his recent trip to Japan, the singer had been battling a severe flu, which he apparently caught from his two young children Paris and Prince, his publicist Raymone Bain confirmed.

Bain said Jackson and his family returned to the U.S. because they had all fallen ill. Jackson was still sick, she said.

"I'm not sure what the diagnosis is. It could be pneumonia," she told 411.

Bain denied that the singer had been hospitalized, but other sources close to Jackson said he has definitely been in the hospital in recent days.

Jackson has battled an addiction to prescription drugs, a problem that has caused his already poor health to be compromised.

The troubled pop star's trip to Japan included a $3,500-a-ticket gala and a nightclub event with fans.

He'd returned to Las Vegas — where he has been living in recent months while reportedly pursuing various business deals — in the last 10 days, sources told FOXNews.com.

There have been rumors that he, sister Janet Jackson and his brothers are considering touring together for the first time in years because the family is in debt and needs the money.

Jackson had lived abroad since his 2005 acquittal on child molestation charges, forsaking his Neverland Ranch in California for Bahrain, France and a castle in Ireland.