AKIPRESS.COM - Actor Charlie Sheen has confirmed he is HIV-positive in a lengthy television interview, and said he has been the victim of extortion and blackmail for years by confidantes who threatened to reveal his condition.

The former Two and a Half Men star said he had been diagnosed with the virus four years ago after he went to hospital suffering terrible headaches and sweating, fearing he perhaps had a brain tumour. Instead, doctors informed him he was HIV positive.

"I am here to admit I am HIV positive," he told presenter Matt Lauer on NBC's breakfast news program Today. "It's a hard three letters to absorb."

"I release myself from this prison today," he said.

His announcement also follows claims he deliberately hid his HIV status from sexual partners. Asked by interviewer Matt Lauer whether it was possible Sheen had either "knowingly, or unknowingly", transmitted the disease to anyone else, Sheen declared it would have been "impossible", reports Sydney Morning Herald.