CCTV still of the woman police would like to speak to PIC: Metropolitan Police/PA Wire

Police probing the murder of a dad-of-two at a star-studded party have appealed for a woman to come forward.

Woman (ringed) whom police would like to speak to PIC: PRESS ASSOCIATION Photo.

Brit Award-winner Jessie J performed at the function hosted by smart-phone company BlackBerry, before Phillip Sherriff was fatally wounded last month.

The married 37-year-old Blackberry employee died in hospital on April 8 after a four-day battle to save his life.

Scotland Yard believes the woman is a vital witness but they have been unable to identify her.

“On the night Mr Sherriff was assaulted, the Pulse nightclub was hosting a party on behalf of BlackBerry, and we are aware that large numbers of people attending the event came from outside London,” said Det Ch Insp Cliff Lyons.

“It is therefore possible the witness we are trying to identify lives elsewhere in the country.

“However, I would appeal for the woman or anyone who recognises her to contact the incident room.

“I would like to reassure anyone who may be worried about contacting the police that they will be treated with the utmost sensitivity.”

Call the incident room with information on 020 8721 4961. Alternatively, call Crimestoppers anonymously on 0800 555 111.

Mr Sherriff had been invited to the BlackBerry function along with a string of celebrities, including rapper Wretch 32 and stars of The Only Way Is Essex.