Johns Creek Mayor Mike Bodker has vetoed a measure that would have allowed the city attorney to divulge privileged information to an outside attorney investigating alleged wrongdoing.

The veto, Bodker’s first since taking office seven years ago, comes a week after the City Council voted to permit the city attorney to cooperate with a probe into the mayor’s actions relating to closed sessions. That vote was 6-0, with the mayor not participating.

By city charter, it requires five votes to override the mayor’s veto.

Bodker said Tuesday he took the action after consulting an attorney who warned him of potential dangers the city could face in waiving attorney-client privilege. Such a step could leave the city vulnerable by revealing proprietary information — such as strategies in land purchases or litigation — to any party requesting it, he said.

“I had no choice because it was the only way to prevent it from moving forward before the damage was done,” Bodker said. “Because in this case, a waiver of attorney-client privilege can never be undone.”

The mayor said he hopes the council will reconsider its methods in running the investigation. He said he it done, but in a way that doesn’t damage the city.

City councilman Randall Johnson, who has spoken for the investigation, said the mayor’s action merely stalls the probe but won’t halt it.

“We passed that resolution to increase transparency,” he said. “It’s obvious that he’s uncomfortable with transparency in discussions with attorneys. It’s obvious he’s trying to slow the investigation down.”