A billboard supporting embattled Toronto Mayor Rob Ford is being investigated by the city.

The city says it's looking into the unauthorized use of its logo on the sign that was erected in a west-end neighbourhood that's home to the mayor's hard core "Ford Nation" supporters.

The phrase "we support mayor Ford" appears on the billboard next to a City of Toronto logo.

The sign also says "Ford = Fiscal Responsiblity," misspelling the word responsibility.

It concludes by quoting the Bible: "Let the one who has never sinned throw the first stone."

An image of the billboard made the rounds on social media Friday, with many Twitter and Instagram users commenting on the typo.

The sign was removed by Saturday afternoon.

It's not clear who paid for the advertisement.

Ford is still clinging to his job after a week of shocking confessions of smoking crack, being in drunken stupors and engaging in erratic behaviour.

Both friends and foes alike are now telling Ford to take time off and seek professional help.

With files from CTVNews.ca staff.