A small chartered plane has gone missing on Indonesian Borneo with four people on board, including an Australian, officials said on Saturday.
"The Cessna aircraft was carrying four people. The captain was Indonesian and an Australian, Peter John Elliott, was on board," National Search and Rescue Agency spokesman Gagah Prakoso told AFP.
"They left the city of Samarinda to conduct a short surveying flight in East Kalimantan province on Friday, but they didn't return that evening."
The aircraft is owned by the the Indonesian company Intan Angkasa Air Services, Prakoso said.
It was chartered by the Australian passenger's Perth-based mining company, Elliot Geophysics International, which specialises in mineral, oil and coal exploration, according to its website.
A team of 20 rescuers are searching through thick jungle, while eight are conducting an aerial search by helicopter and plane, Prakoso said.