The two incidents were featured on the BBC's Crimewatch programme last month and a team is drawing up profiles of all men identified as possible culprits.

More than 80 calls were made on the night the show was broadcast and a further 20 have been made since.

Detectives have branded the rapist "dangerous" after he attacked a 23-year-old prostitute at gunpoint after picking her up from on Allen Street in Neepsend and driving her to an isolated spot.

Three weeks earlier - on Christmas Day - he picked up a 42-year-old woman from the red light district and also produced a gun, but the woman knocked the firearm out of his hand and fled.

Det Insp Richard Liver-sidge, leading the hunt for the attacker, said: "Despite the response the crimes still remain undetected and there may be people out there still considering whether to pick up the phone and ring the police - they could hold the vital piece of information we need.

"We have a great deal of information about this man and can eliminate people quickly so I would rather go and see people who have no connection at all rather than miss out on the person who did this.

"This man may strike again so it is vital people come forward and tell us what they know."

The man was white, aged around 40, 5ft 6ins tall and stocky with a bald or shaven head.

He drove a silver Vauxhall Astra estate which had a baby seat in the back and he had tattoos on his thighs.

Anyone with information should call 0114 296 4040 or Crimestoppers anonymously on 0800 555111.

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