Mr McCloy told the Newcastle Herald that someone had sprayed the initials DOS on the Telstra building on the corner of Darby and Hunter streets about 12.20am on Friday last week.

He said he had tried unsuccessfully to clean the wall with a high-pressure hose and would be forced to render and paint it.

Mr McCloy wants to "run the guy through the courts" to force him to pay for the repairs and as a warning to other would-be graffiti artists.

He has passed video footage and images of the masked person he believes is responsible to police but is now posting his own reward to catch the culprit.

"I'll put a $1000 reward up for anyone who can nominate and identify this kid," he said.

"The reason to do that is to find him, have the police charge him and make him pay for the restoration, even if I have to run him through the courts.

"This has hardly been done before, but there's only one way to send a message to them that they're destroying other people's property."

Mr McCloy, whose office is in the Telstra building, believes the DOS tag has appeared elsewhere in Newcastle.

He has long railed against the "rampant" graffiti he says reflects "social decay" in inner-city suburbs.

"Thank goodness for some of those murals which have gone up now and covered a lot of the bad spots, but that won't stop them continuing to deface our city," he said.

"It lowers the tone of the city. No one cares about what the city looks like, the cleanliness, the tidiness."

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