"I managed to get this Auckland Transport car ticketed and towed from a mobility park," the photo's caption said.
Senior Auckland Transport officials did not know of the incident until contacted by the Herald, but an investigation has started.
"We are investigating now who had this fleet vehicle," a spokeswoman said. "Auckland Transport views this as a serious incident worthy of a formal investigation.
"We take this matter extremely seriously. The staff member will pay the ticket."
Parking permits are administered by CCS Disability Action, and chief executive David Matthews said the photo reflected "a very selfish attitude" among Kiwis.
"That picture will just demonstrate the issue we are all facing - that people, despite knowing that they shouldn't be parking in these spaces, choose to do so.
"That reflects to me a very selfish attitude and the need for us all to be reminded that these spaces are for people who really need them. It's disappointing to see the level of abuse of these carparks continuing and that it includes people who should know better."
He believed fines should be increased in line with international standards that were more than $1000 in some countries.
More than 100,000 mobility parking permits are held by New Zealanders.