A row of parked vehicles in North Drive, Ruislip, were shown to have been heavily scratched, scraped and dented yesterday.
Witness Hollie Cooper said she had seen a collision involving a lorry and the 15 cars and she took photographs as evidence.
No arrests have been made yet, police told Hillingdon is Here this evening.
Like this story? Get free email newsletters via the form below
Free email newsletter
Below: The pictures the police are assessing in the investigation. All pictures taken by Hollie Cooper.
But Ms Cooper, speaking to Hillingdon is Here, explained that the damage had deeply upset owners of the affected vehicles.
She said: “One woman managed to find me yesterday for the evidence, she was in tears with how bad her car was.
“My colleague was the one who saw her go up to her car crying, so he sent her to our office as he knew I had picture evidence for her.
“When I was walking back to my car at around 5.30pm, I bumped into the owner of one of the other cars who was overly annoyed at what had happened and said she had just got her car fixed from a previous accident.”
Temporary Chief Inspector Rob Bryan provided a statement, which said police were aware of the pictures being shared on social media.
The statement read: “Officers have visited the scene to assess the damage caused and enquiries continue. There have been no arrests at this stage.
“We take all allegations of crime seriously and in this instance a report was not taken as it should have been due to a miscommunication. We have since made contact with the informant (Ms Cooper) to apologise and obtain further details.
“We would always encourage members of the public to report such incidents and where possible provide evidential material, including photographs, if it can be obtained without putting anyone at risk.”
A number of people have contacted Ms Cooper for the pictures.
She saw the collision occur at 9.45am, with car alarms being set off as a result, she said.
During her lunch break she printed pictures and put them on the cars involved so they could claim on their insurance policies and contact police.
She said she had been turned away from the police station originally, but police had since apologised and said there had been a miscommunication.