Surrey RCMP are investigating an allegation of a "sexual nature" involving a Delta police officer.

The incident happened between two off-duty police officers and was brought forward to the Delta Police Department last month, Delta police said in a media release.

Police determined the allegation warranted a criminal investigation. The incident did not happen in a police facility and involves no members of the public.

One police officer has been suspended with pay.

Delta police provided no further details.

Surrey RCMP said it is in the preliminary stages of its investigation.

In a statement, Delta police Chief Neil Dubord said the department will take time to "look inward" to ensure its policies are appropriate and understood by police officers and employees.

"This allegation is extremely concerning," Dubord said in a statement.

"Police officers are — rightfully so — held to a higher standard both on and off-duty. That is why I wanted to be as open as I could about the process that's now underway. It is important that this allegation be investigated fully by an independent police department."