The woman, who was on holiday with her boyfriend, was told by staff at their hotel that the bikini was not appropriate to wear to the beach.
However, she chose not to heed their advice and wore it again, when she caught the attention of local police.
According to Major Jess Baylon, police chief of Malay town on the island, the tourist was apprehended by the authorities before being fined PHP 2,500 (£38.58) for her “erotic and lewd” swimwear.
“We have our own cultural values as Filipinos and Asians. They should be able to respect that,” said Natividad Bernardino, chief of the Boracay Inter-Agency Management and Rehabilitation Group (BIAMRG).
“There is no dress code. Maybe it is just common sense.”
Bernardino added that hotel and resort owners in the region frequently advise tourists on island protocol, including how to dress.
Major Baylon said the incident is an “eye opener for resort owners to brief guests to dress appropriately”.
The police chief said that the tourist’s boyfriend said the string bikini was “normal” to wear in Taiwan.
“Her boyfriend said, ‘It’s quite normal for us in our country and that was her way to express herself with confidence’,” Major Baylon said.
Adventure World in Perth, which describes itself as a “family-friendly park”, posted an infographic on its Facebook page that included illustrations of “cheeky” swimwear.
Following a backlash, a second post was shared on Facebook in which the water park defended the update to its dress code, adding that it is “not gender specific”.
“To those who have taken offence, we apologise,” the company wrote.
“As a family friendly venue, we feel it is appropriate.”