A group of Australians detained in Papua after landing there illegally last Friday have told officials they travelled to the tightly controlled province to assess tourism opportunities.

The three men and two women landed in the Papuan town of Merauke without Indonesian visas, flight approval or security clearance.

The five have told Australian officials they flew to Papua to assess tourism opportunities, believing they could obtain visas on arrival.

Australian embassy officials are on their way to the tightly controlled province to assist the five who remain under guard in a hotel.

Foreign Ministry spokesman Teuku Faizasyah said Indonesian police are still investigating the reason for their arrival in Papua.

“It’s probably mere stupidity,” he said.