"This is something we have to rethink," Apichart said.
The global intelligence company Stratfor said that passport fraud is common among human traffickers, drug smugglers, arms merchants, money launderers, fugitives and pedophiles — many of whom end up in Thailand. "Only a very small percentage," of those involved in the underground trade have terror links, Stratfor said.
Nevertheless, the threat remains a concern. After the Sept. 11 attacks, Thailand — under pressure from Western governments — vowed to crack down.
In 2004, police arrested a Bangladeshi who allegedly supplied forged passports to al-Qaida-linked terrorists, including the mastermind of the 2002 Bali attacks. In 2010, authorities nabbed Pakistani Muhammad Butt, who police believe provided false passports to suspects in the Madrid train bombings.
Two years later, Thai officers arrested Parknejed Seyed Ramin for alleged involvement in a passport racket that was thought to have aided suspects in a bomb plot discovered in Bangkok on Valentine's Day the same year. Police said Ramin's gang had been running a lucrative, 5-year-old forgery business worth millions of dollars.
Governments like the United States have fought back by embedding digital chips inside passports that contain a photo of the passport holder and information about the owner. Stratfor said that has made it tougher to alter photos, but chips can still be hacked.
In Thailand, passport forgers now use advanced technology, and their clients can evade capture by selling them to lookalikes who resemble the owners.
A senior Thai intelligence official, who has spent years hunting down passport theft rings, said investigators are currently tracking about 10 major syndicates in Thailand.
Most were run by nationals from Pakistan, India, Iran or Central Asia he said, for clients that are mostly illegal migrants. The fact that travel documents are often stolen or forged in one country and used in another, though, "makes it hard for the governments to follow and arrest them," he said.
In Phuket this week, police called meetings with dozens of owners of motorbike rental shops and told them to take copies of passports instead of the originals. It was unclear, though, how or whether they would enforce it.
Associated Press writer Todd Pitman contributed to this report from Bangkok.