The company responsible for illegally allowing people to live in the 61 Molesworth St building had illegal tenancies in another quake-damaged building earlier in the year.
PrimeProperty Group may face prosecution for renting office space to people in the building, which will be torn down after last week's earthquake. It has now been revealed the company also had people living in a quake-damaged building on Wakefield St.
Wellington City Council spokesman Richard Maclean said council received a complaint in September about people living illegally in the former Greater Wellington Regional Council building on Wakefield St.
"Our inspectors went along and inspected the building. It was obvious that it had been used as accommodation," Maclean said.
"It appears that it had been used for fairly large parties on one floor."
The council told PrimeProperty Group to clear out the tenants, as the building was not registered for residential accommodation.
"We said stop doing this, cease and desist," Maclean said.
"It did suffer quake damage in the 2013 quake. Whether it was supposed to be occupied or not is a moot point for the engineers but it certainly needed a fix-up. One of the reasons the regional council left was because there were concerns about the stairwell."
Maclean did not believe the "fix-up" had happened before tenants began living illegally in the building.
A decision on whether to lay charges against PrimeProperty Group is yet to be made, as the council is focusing on earthquake clean-up.
"We've got much more urgent work on our plate at the moment around the city. We will obviously in the next few weeks take a look at the situation."
Maclean said there was "a likelihood" charges would be laid, "but obviously we will look at all the usual things that you look at before you decide to take the steps of laying charges or prosecuting. It's a big step to take."
Asked whether the earlier tenancies in Wakefield St would have an impact on the decision to prosecute, Maclean said council would consider all the information in its decision.
While investigating other buildings for illegal tenancies was not a priority at the moment, the council would be happy to investigate any information received.