A cleaner at the University of Kent in Canterbury has admitted being the bomb hoaxer who rang in three fake threats.

Staff also discovered two devices, one a bag and a second a plastic bottle both with protruding wires.

Now Vanessa Relton is to undergo a psychiatric assessment before being sentenced for the offences, which led to the buildings being evacuated.

She was caught when a security guard who took one of the bomb threats recognised her voice and alerted police.

But we can reveal that Relton, 40, of Cromwell Road, Whitstable has previous convictions for similar offences 24 years ago and an arson in 2001.

She was remanded on bail until the sentencing hearing in May but the judge ruled she had to wear an electronic tag and remain at her home between 8 pm and 6 am.

Judge Simon James also ordered her to provide the police with her mobile telephone number and not to use any other phone without alerting officers of the number in advance.

He said: “These are serious and alarming offences especially in the current climate. She not only makes bomb hoaxes but also places items in a public area."

She pleaded guilty to three offences of communicating false information with intent to make people believe a bomb had been planted in the university library on September 23 and on December 1 and 2 last year.

Relton also admitted placing a plastic bag with wires in the university’s Templeton Library intending people to believe it was a bomb on September 23 and a bottle with fluid and wires on December 1.

Canterbury Crown Court heard that Relton is claiming she was under stress when she made the calls.

Her barrister Peter Forbes said the previous convictions “date back a considerable period of time.”

He added: “Of course, these offences are alarming ones and the court’s choices for sentence are prison or a hospital order.

“These were phone threats made in September 23 saying there was a bomb in the library which resulted in evacuation and disruption.

“And then on two days in December when a plastic bottle with wires coming out was placed in the library. As far as we can tell it was dismissed by the university and the second device, similarly amateurish, was dismissed by a police constable, “ he said.

The barrister add: “Of course there was disruption and evacuation from a number of buildings.

"She made the threats to a security officer who recognised her voice as someone employed as a cleaner at the premises. The actual danger that she posed was nil.”