A woman was sexually assaulted after sharing a taxi home with a man she had met at the pub earlier in the evening.
Officers at Herts Police are investigating the serious sexual assault and appealing for information and witnesses.
The offence happened after the victim - a woman aged in her 40s – had left the Rose and Crown pub in the Old Town between 2am and 3am on Saturday, May 20.
She had met the offender earlier that evening in the pub before sharing a taxi home with him. After she got out of the taxi to go home the offender followed her and sexually assaulted her before making off.
He is described as an Asian man, who was wearing jeans and a top with a blazer-type jacket.
Detective Inspector Jason Keane from the Sexual Offences Investigation Team (SOIT), said: “We know that earlier that evening the victim had been speaking to the offender while inside the Rose and Crown pub.
“They then left the pub between 2am and 3am and got a taxi, along with another man, from outside the White Hart pub in High Street, Old Town.
“I am appealing for anyone who was in the Rose and Crown on Friday night (May 19) and believes they saw the offender or knows who he is to get in touch with police.
"I would also like to speak to anyone who believes they saw the victim and the offenders get into a taxi outside the White Hart pub in the early hours of Saturday morning.”
Anyone with information is asked to contact Hertfordshire Constabulary via the non-emergency number 101, quoting crime reference D1/17/4124.