A murder investigation has been launched following the death of a woman who suffered serious chemical burns when she was "caught up in an altercation" in High Wycombe.

Thames Valley Police have released a fresh witness appeal to help locate the bottle which contained the chemical. 

READ MORE HERE: Chemical bottle image released as police hunt killers

At 4.48pm on Saturday 3 June a group of men became involved in fight in Frogmoor, High Wycombe.

Marlow resident, 47-year-old Joanne Rand, was sitting on a nearby bench when she was sprayed with a liquid, believed to be an alkaline substance, after a bottle was kicked during the fight.

She sustained “serious” burns and was rushed to Stoke Mandeville Hospital for treatment, but was later discharged.

However she was readmitted to the hospital on Friday, June 9 where she sadly died yesterday.

A Home Office Post-Mortem examination will take place in due course.

An 18-year-old man from London was arrested on suspicion of assault occasioning GBH on Tuesday and was released under investigation while enquiries continue.

Xeneral Webster, 18, of Westway, Hammersmith and Fulham, London, was charged on Tuesday with one count of robbery in connection with the incident.

He appeared at High Wycombe Magistrates’ Court yesterday (June 14) and was remanded in custody.

Senior investigating officer Detective Superintendent Paul Hayles, from Buckinghamshire Force CID, said: “A team of detectives is continuing to investigate this incident and carry out enquiries.

“I would like to appeal to the public, particularly those who live or work between Frogmoor and the railway station in High Wycombe, to be aware of the bottle photographed which may have been discarded possibly in or with a dark coloured shoulder bag in the area.

“I would like to warn members of the public not to touch the bottle if they see it but to instead contact police as soon as possible. The bottle is white and has an orange or red hazard label on the side.”

Superintendent Ed McLean, Local Police Area Commander for High Wycombe, said: “A thorough investigation is taking place in relation to this incident.

"People in the community may also notice police search activity taking place.

"They should not be concerned however if anyone has any issues they wish to raise or any information they can approach and speak to an officer.”

If you have any information relating to this case, please call 101 quoting reference 'URN 1902 3/6', or contact Crimestoppers anonymously.