Homicide not ruled out in Jackson probe

The probe into Michael Jackson's death stepped up yesterday after investigators subpoenaed medical records and a leading police officer refused to rule out homicide.

Coroners called for any records held by Mr Jackson's many doctors to be presented, "including radiology and psychiatric records," the Los Angeles Times reported, as part of an ongoing investigation into the singer's death aged 50 on June 25.

Los Angeles police chief Bill Bratton said his department was looking into Jackson's "prescription drug history, the doctors that he's dealt with over the years.

"Are we dealing with homicide? Are we dealing with an accidental overdose? What are we dealing with? So as we are standing here speaking, I can tell you, I don't have that information," he told CNN.

The pop superstar's 79-year-old father Joe Jackson meanwhile told ABC News that he remained suspicious of the circumstances surrounding his son's death.

"I do believe it was foul play," Mr Jackson said. "I do believe that. Yes."