A Nepalese friend of Ryan Sean Davy said that the climber was being questioned by tourism officials.
Friends say Mr Davy has no cash, which is why he mostly travelled on foot.
Mr Davy, 43, says he climbed alone to a height of 7,300m (24,000ft) before being found hiding in a cave by officials who confiscated his passport because he did not have a permit to climb Everest.
He has apologised but complained of being treated harshly by officials.
He is due to appear in court today where he is expected to receive a heavy fine.