Jason Metcalfe, 32, was told he faces spending many years in prison after he pleaded guilty to raping a 35-year-old prostitute who he had picked up in Northampton's red light district.

He was told by Judge Charles Wide QC at Northampton Crown Court yesterday he will receive either a life sentence or an indeterminate term for the public's protection.

But the court was told he was still being investigated by Northamptonshire Police for similar attacks on prostitutes.

Bearded and dishevelled Metcalfe, of Montague Crescent, Rye Hill, in Northampton picked up the vice girl, who cannot be named for legal reasons, offering her money to spend the night with him.

But while they were walking through the Kings Heath area of town, she was seriously assaulted and raped.

She suffered a number of injuries, including a suspected broken nose.

Matthew Lowe, prosecuting, told Judge Charles Wide QC of Metcalfe's previous convictions which include rape offences and the indecent assault of a man.

He added: "The defendant is currently being investigated for similar offences against similar women."

Metcalfe, who only spoke to confirm his name and guilty pleas, admitted rape, assault by penetration and inflicting actual bodily harm.

Judge Wide said: "The court will have a life sentence in mind and imprisonment for public protection so of course, the risk he poses will be at the forefront of my mind.

"I will want a pre-sentence report and in the light of the defendant's antecedent history and this matter of undoubted gravity, the court will be considering life imprisonment or an indeterminate sentence so the question of risk will be the most important part of the report."

He added that despite the ongoing investigation and any possible future charges, sentencing next month would not be held up.

The judge, who further remanded Metcalfe in custody, adjourned sentencing until next month.