Perivale Park in Ealing was patrolled by police officers on Wednesday afternoon (July 25) after they were called to reports of an assault nearby.
Police attended reports of an assault in Ruislip Road at around 4pm.
According to Metropolitan Police officers attended but found both the suspect and the victim had left the scene by the time they arrived.
A Metropolitan Police spokesman said: "Police were called to reports of an assault in Ruislip Road at around 4pm but by the time officers arrived both the victim and the suspect had left the scene."
At 5.30pm the Perivale police team posted on social media that its officers had patrolled the park following the incident.
A Perivale police tweet read: "The team conducted more joint patrols with Parkguard in Perivale Park this afternoon. During these patrols we took a crime report for an assault that had occurred nearby."
Perivale police has been contacted for more information about the incident.