Officials learned of the plot and Doherty was moved to a high-security unit, Sky News said in an exclusive report Friday.

Guards searched Doherty after receiving reports he was injecting heroin in his cell. The singer appeared calm during the search, a source told Sky News.

Doherty has battled addiction for some time and has had several stints in drug rehabilitation programs.

"Pete is in the segregation unit for his own safety, and partly because he asked for the move himself," the source said.

Doherty was jailed last week for violating terms of his probation and is expected to be released in May.