A former royal aide who escaped from a British prison while serving a life sentence for murder is not a danger to the public, police have insisted, Sky News reported.

Jane Andrews, who was sentenced to life for killing her boyfriend Tom Cressman, failed to return to East Sutton Park prison in Kent on Sunday night, according to Sky News.

Officers described the Duchess of York's former dresser as vulnerable, with her disappearance coming days after an apparent suicide attempt.

"We have no information to suggest she is a threat to the general public," Kent Police Assistant Chief Constable Andy Adams said, according to Sky News.

"However, we must be mindful that in 2000 she was convicted of murder."

Andrews, who was only moved to East Sutton Park on November 18, was reported missing from the jail after she was last seen at 7 p.m. on Sunday, according to Sky News.

Click here for more from Sky News.