Detectives investigating the murder of a 51-year-old man who was stabbed to death on a train have launched a fresh witness appeal for anyone who saw a man and a woman "acting in an unusual manner".

Lee Pomeroy was stabbed nine times in the incident which happened at Horsley station on Friday, January 4.

Darren Pencille, 35, is charged with his murder and possessing an offensive weapon.

His partner, mother-of-one Chelsea Mitchell, 27, is charged with assisting an offender.

Mr Pomeroy, who would have celebrated his 52nd birthday on Saturday, boarded the 12.58pm train service between Guildford and London Waterloo at London Road station on Friday afternoon.

British Transport Police are appealing for witnesses who saw a man and a woman with a child in the Frensham Great Pond area, near Farnham, between 5.45pm and 6.35pm on the same day.

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Detective Chief Inspector Sam Blackburn said: "Since Friday afternoon, a dedicated team of detectives have worked diligently in piecing together the events before and after the killing.

"Our enquiries have led us to believe the suspects briefly stopped at Frensham Great Pond car park, on Bacon Lane after 5.30pm on Friday afternoon.

"We are therefore looking to speak with anyone who was at the site and saw a man and a woman acting in an unusual or out of character manner.

"They would have been travelling with a young child at this point and we understand they would have arrived and departed in a blue Vauxhall Corsa.

"If you were at the Frensham Great Pond car park during this time, please do get in touch as you might hold information which could help us uncover any new evidence."

A BTP spokesman said that a post-mortem examination showed that Mr Pomeroy died as a result of multiple stab wounds including an injury to his neck.

He added that searches had been carried out in the Clandon area of Surrey and at a property in Bognor Regis, West Sussex.

Mr Blackburn added: "Our family liaison officers are providing Mr Pomeroy's family with support as they continue to come to terms with Friday's devastating news. The family have asked for privacy as they grieve the loss of Lee."

Mr Pomeroy, who lived in Guildford and owned an IT firm, was described by his family as "an honourable man and would always help somebody who was in trouble".

In a statement, the family said he was a cultured man, who loved his 50-year-old wife Svetlana Pomeroy.

"He was a devoted family man and did everything for his family," they said.

Pencille and Mitchell appeared at Guildford Crown Court on Monday and were remanded in custody until the next hearing on February 7.