Convicted mass murderer Charles Manson has been transferred from a California prison to a hospital for an undisclosed medical issue, according to media reports.

Manson was seriously ill, a source told the Los Angeles Times on Tuesday, but could not provide further information.

TMZ reports that Manson was transported to a hospital in Bakersfield, California, about an hour from California State Prison in Corcoran, where he is being held.

A spokesman for California Department of Corrections and Rehabilitation had no comment, citing inmate privacy issues.

Charles Manson was convicted to life in 1971. Photo: Getty.

Manson, who was sentenced to life in prison, directed his mostly young, female followers — known as the Manson Family — to murder seven people in August 1969 in what prosecutors said was part of a plan to incite a race war between whites and blacks.

Manson was convinced that a race war was set to break out in the US, citing the Beatles song Helter Skelter as evidence of his theory.

He encouraged followers to commit a string of vicious murders, one of which involved Sharon Tate, at the time married to film director Roman Polanski.

Manson was convicted in 1971, but was spared the death penalty.

More to come.