Six Chinese men have successfully landed on Australian territory by boat, in an apparent blow to the Turnbull government's claims to have stopped the boats.

Fairfax Media can reveal that a boat carrying six Chinese nationals and an alleged Papua New Guinean people smuggler – all of whom were men – reached Saibai Island on August 20.

The boat that reached Saibai Island is understood to be much smaller than this asylum seeker boat from 2013.

Saibai Island is a low-lying island about four kilometres from Papua New Guinea and home to about 300 people. It is nearly 150 kilometres north of the Queensland mainland but is part of the state.

As recently as Monday, Immigration Minister Peter Dutton boasted that "we've not had a successful boat now in well over 1000 days".