The issue is so fraught that even the word "Rohingya" itself is widely disputed. Buddhists say the term was made up to obscure the Muslim population's South Asian heritage; they do not accept the Rohingya as a separate ethnic group, and instead call them "Bengali" — a reference to the belief they are in fact Bangladeshis who entered illegally.
While some Rohingya have lived in Myanmar for generations and have documents to prove it, others arrived more recently. There is little distinction between these two groups, though. During the last official census in 1983, the Rohingya were excluded.
In places like Sit Thet Maw, Rakhine Buddhist elders believe they are on the front line of a population explosion, and they are worried.
Some 70 years ago, there were about 1,000 Buddhist and 100 Muslim inhabitants here, according to Said Thar Tun Maung, a 59-year-old Rakhine who works as a local government administrator. Today, the Buddhists are a minority: They number just 1,900, compared to 4,000 Rohingya residents.
Tun Maung blamed the demographic changes on higher birth rates among Muslim families, and the illegal arrival of new migrants hunting for fertile farmland and good fishing. Several thousand more Muslims arrived in October after Rakhine mobs burned their homes in the town of Kyaukphyu, swelling the Muslim population here even further. The refugees' presence is considered temporary — they are currently camped along the beach beside their ships.
"This is our land," Tun Maung said. But "it's slowly being taken away from us, and nobody is doing anything to stop it."
The AP team that visited Sin Thet Maw observed four-man government teams conducting interviews with dozens of Muslim families. The Rohingya live in a separate part of Sin Thet Maw that is completely segregated from the Buddhist side of the village by a wide field running hundreds of meters (yards) inland.
Most of those interviewed had temporary national registration cards that were issued by authorities ahead of elections in 2010 in an apparent effort to secure their support. The cards granted the Rohingya the right to vote, but they were stamped with a major caveat that read: "Not proof of citizenship." Most also showed government-issued forms on which their family members had been registered.
There was one question, though, that the officers did not ask — the one that mattered above all the rest. It was represented on the forms by a blank line beside the entry: "Race/Nationality."
After each interview, the officers filled in the empty space with the words: "Bengali," or, "Bengali/Islam."
The consequence of such answers is unclear. One officer, Kyi San, said only: "We're collecting data, not making decisions on nationality."
But several Muslims interviewed by the AP complained that officers refused to classify them as Rohingya, declaring that "the Rohingya do not exist." One man said he was beaten after refusing to sign a form identifying himself as Bengali.
Chris Lewa, of the Arakan Project, said the use of the word Rohingya was common among Muslims in some parts of Rakhine state, but rarely used in others like the capital, Sittwe.
But since the latest unrest began in June, Muslims from packed refugee camps to the remotest island villages are almost uniformly calling themselves Rohingya.
"Being Bengali means we can be arrested and deported. It means we aren't part of this country," said Zaw Win, one of the Muslims who had been interrogated. "We are not Bengali. We are Rohingya."
Associated Press writers Aye Aye Win and Yadana Htun contributed to this report.