Prime Minister Stephen Harper has taken his law and order agenda to a new level by making an appearance in the police procedural TV series Murdoch Mysteries.

Harper and his daughter Rachel are said to be huge fans of the show, which films in Toronto. The pair visited the set on Friday where the prime minister filmed a 90-second scene in which he plays a desk sergeant.

Shaftesbury Films kept mum about the appearance until after the shoot, releasing a statement late on Friday.

Set in 1890s Toronto, the series is based on Canadian author Maureen Jennings's Detective Murdoch mystery novels. Played by Yannick Bisson, forensics detective William Murdoch solves crimes by using techniques that were advanced for his time

Now in its fourth season, the show is broadcast in more than 100 countries.

Shaftesbury CEO Christina Jennings told the Globe and Mail the prime minister was committed to his part and gave a few notes to the show's writers.

"He was pointing out a couple of little bits of historical accuracy," said Jennings.

The show also had to get permission from the actors union, ACTRA, before Harper could play a role.

This isn't the PM's first cameo on TV. He also did one on CTV's Corner Gas.