A vaccinated man has tested positive in Brisbane after spending two weeks in hotel quarantine, perplexing state health authorities. 

The man aged in his 40's returned from China earlier in the month, testing negative three different times in quarantine.

When tested later by his GP, a new infection was found in his system, which is currently considered low risk by health officials. Queensland Chief Health Officer, Dr. Jeanette Young says genomic testing is in process to understand where the man got the infection.