A photo of a London Police officer having her body painted in blackface has prompted an internal police investigation and harsh criticism from the city's mayor.

Several photographs of Const. Katrina Aarts having the makeup applied were posted on an Instagram account, police said Friday.

The photos were sent to the mayor's office earlier in the week by a concerned citizen. The pictures were then forwarded to the deputy chief on Thursday, prompting him to call an investigation.

"We take these matters very seriously," deputy chief Stephen Williams said. "We understand that many members of the community have expressed some concern and offence to this and it's our responsibility to address that."

Williams said the service's professional standards branch is investigating the photos, which were sent to CBC News.