Authorities will stop an illegal festival celebrating cannabis planned for public reserve near Dunedin this weekend.

Photo: 123rf.com

The two-day Harvest Festival is set to start on Saturday at Woodside Glen, a Dunedin City Council reserve.

Organisers have sold tickets to the festival where musicians including Tiki Taane were billed to play, and planned to have an R18 area where cannabis consumption is allowed.

But council chief executive Sue Bidrose said organisers would be issued with a trespass notice today as the festival is illegal.

"We have a pretty standard process where we don't let people rent council-owned facilities that are owned by the ratepayers specifically for the purpose of encouraging illegal activity, whatever that activity might be.

"We have been absolutely consistent about that the whole way through."

Ms Bidrose said the council was working with police to make sure no laws were broken, including preventing the public from accessing public land.

The council was not taking a moral stance but had concerns about public safety.