He said he believed it was one person involved and was worried that somebody would light a fire so close to the marae's main building.
"Our wharenui is only eight to 10 metres away from where he lit the fire and it's a worry that we have an arsonist running around lighting fires like this. If it had got to the wharenui it could have been a disaster."
The arson brought back memories of a fire that destroyed the marae's wharekai (dining room) in December 15 due to an electrical fault.
Mr Potter said the arson and vandalism had been referred to police and he hoped an arrest would be made.
He said if anybody was opposed to Ngati Hau's stance, the matter should be debated on the marae, which is the appropriate place, not try to burn the place down.
Mr Potter said the marae was sacred to the hapu and the fence was still part of the marae complex.
The marae committee met on Thursday to discuss the issue and had agreed to take the anti-mining signs down for now.
Mr Potter said new signs would be erected in the new year and the local community would be keeping a close eye on the marae in case the arsonist came back.