Milford Dart Ltd is applying for a concession from the Department of Conservation to build a 12-kilometre tunnel directly linking Milford Sound and Queenstown.
A company director, Michael Slee, appeared at the hearings on Friday to respond to submissions opposing the proposal.
Mr Slee says his company spoke to 128 tourists who had just taken the bus journey to Milford Sound and back to Queenstown, and almost all said they would not recommend it to others due to the 12-hour bus trip there and back.
He says how unpleasant the bus trip is is the country's dirty little secret, which never gets discussed by tourist operators.
