Toronto police are looking for a vandal who defaced a memorial honouring two fallen officers.

A vandal splattered paint on a memorial sign for two officers near the Don Valley Parkway Bridge over Underpass Gate.

The bridge was named to honour Det. Michael Irwin and his partner Det. Douglas Sinclair who were killed in the line of duty in 1972 by an armed man.

Irwin left behind an extended police family. His son, his grandson and his niece are still on the Toronto police force.

In fact, Insp. Steven Irwin reported the vandalism to the station after he received a call from Irwin's niece who spotted the sign while driving Tuesday night.

Const. Steve Irwin, Irwin's grandson, was the officer dispatched to investigate the vandalism.

"(The vandal) might not realize the significance of this and might just dislike the police. But I would hope they would do the right thing and surrender themselves," Insp. Richard Hegedus told CTV Toronto.

The city named the bridge in the fallen officers' honour last year.

With a report from CTV Toronto's Tamara Cherry