"We received a report about this case from the health ministry on Dec 25 and officials will be visiting tattoo parlours today to verify this claim," said Bali health department chief Nyoman Sutedja.
"At this point, we are still investigating. We can't say for sure if the patient caught the virus from getting a tattoo or sexual contact," he added.
There are currently 4,200 HIV/AIDS cases on Bali, Sutedja said.
Australian health authorities on Dec 23 said a patient diagnosed with HIV probably contracted the virus while being tattooed on the island. They did not reveal any details of the individual concerned.
More than a million tourists visit Bali every year to enjoy its white, surf beaches, nightlife and Hindu culture.
Indonesian officials said last year that the number of known HIV/AIDS cases on Bali was soaring, with one in four prostitutes reported to be HIV-positive and the number of infections jumping almost 19 per cent from the year before.