A Buckinghamshire Council social worker and her sister who were both found dead in a London park sparking a murder investigation were stabbed to death, it has been revealed.

Bibaa Henry, who had been in Fryent Country Park in Wembley celebrating her 46th birthday with a group of friends and family, was later found dead with her sister Nicole Smallman.

The pair had been reported missing after failing to return home from the park on June 5 and their bodies were found on Sunday afternoon, June 7.

A post-mortem found they had both died as a result of stab wounds.

The Met Police say they are "confident" the pair were killed by a stranger and not someone they knew.

Police are still desperately trying to piece together what happened to the "well-respected, well-liked and highly valued" social worker and her sister.

According to her LinkedIn profile, Bibaa had worked at the council since July 2017 and was a senior social worker.

Earlier in the week, Cllr Mark Shaw, who oversees children's services at the council, paid tribute to the "committed" social care worker, adding that she was "very popular" with her colleagues.

Detectives investigating the sisters' murder say they have identified two "significant" lines of enquiry.

Detective Chief Inspector Simon Harding, Specialist Crime, said: “This is an unthinkably harrowing and tragic incident and my first thoughts remain with Nicole and Bibaa’s close family and friends who are going through the most unimaginable pain and suffering.

“There have been a number of factors involved in both the incident and the aftermath which have required extra time and care in enabling us to create a clear picture of what has taken place. But what we can now say with some certainty is that Nicole and Bibaa were murdered by someone who was unknown to them.

“Enquiries continue at pace, and an ongoing extensive search of what is a significant crime scene – including a pond - continues to yield evidence. My officers are also currently trawling through hundreds of thousands of tonnes of rubbish from a local refuse depot in search of items of relevance to the investigation, which we believe were accidentally cleared from the scene when mistaken for rubbish.

“Whilst we tirelessly work to identify the individual responsible I am asking the public for their help with two points.

“We believe the suspect received injuries during the incident which have caused significant bleeding. Do you know anyone who has been wounded in the last week who is unable to account for their injuries? Has someone returned home and perhaps acted suspiciously or tried to hide something from you?

“We also believe the suspect left the park via the Valley Drive entrance. Did you see anyone acting suspiciously in that vicinity during the evening of Friday into early hours of Saturday? You may have noticed someone who was injured.

“If you have information on either of these specific appeal points - no matter how insignificant it may seem - please contact us.

"At this stage we don’t know why this awful attack took place and any information we can gather will help us further put the pieces of the jigsaw together.”