Overnight rain has helped subdue a bushfire which has been burning on an island off Brisbane for several days, authorities say.

The fire, which had a 400-metre front, has been burning on the popular tourist destination of Moreton Island since Wednesday.

It broke out north of Cowan Cowan, sparked by a vehicle fire, and had scorched more than 1300 hectares of swampland and forest by Saturday morning.

Backburning has protected Bulwer township and Comboyuro camp grounds and safeguarded Tangalooma resort, Queensland Parks and Wildlife Service spokesman Anthony Contarino says.

"Approximately 1300 hectares of swamp and forest vegetation has burned along the western side of Moreton Island and the incident has been divided into two sections at Bulwer and Cowan Cowan," Mr Contarino said.

"Backburning activity has blacked out areas surrounding Bulwer and Cowan Cowan, which are considered secure along with Tangalooma Resort.

"Further planned backburning has been scaled back as a result of the overnight rain."

Mr Contarino said camp grounds along the western side of Moreton Island would be assessed on Saturday with the aim of having them reopened.

Ground crews would continue to monitor all fire areas.

- AAP