Thai police have broken up a major fake passport ring led by an Iranian known as “The Doctor” which sent hundreds of passports to Middle Eastern customers trying to enter Europe, authorities said on Wednesday.

The kingdom has long been a hub for a forged document industry serving human traffickers and other criminals.

Five years of investigation culminated in Monday's arrest of the alleged Iranian mastermind Hamid Reza Jafary who had learnt his skill from his late father, police said.

The 48-year-old had for many years been crafting sophisticated forgeries from his home in Chachoengsao province east of Bangkok, they said.

“He (Jafary) produced passports for people from countries including Iran, Syria and Afghanistan who were escaping wars and wanted to enter Europe,” according to immigration police commander Lieutenant General Nathathorn Prousoontorn.

“The Doctor” confessed to the crime and could face a decade in jail if convicted, he added.

Clients emailed the Iranian forger their photos and specified the country for which they wanted a passport, the commander said, adding that Jafary guaranteed his top-quality counterfeits would not be detected by border officials.

The forged documents were then sent via private courier companies or delivered to clients in Thailand by middlemen, who ensured that Jafary never met customers directly.

It was not immediately clear if “The Doctor” provided passports to people fleeing to Europe during the current migrant crisis.

Jafary's fake passports were the “best quality in the market”, although he was unable to copy the latest microchipped travel documents, Natthorn said.

“He himself used six different passports - three from Brazil, and one each from Peru, Portugal and New Zealand,” the officer added.

“The Doctor” was wanted by security agencies in several foreign countries, especially in the EU and Japan, according to a police press release.

Five Pakistani middlemen were also arrested in raids in and around Bangkok for assisting the forgery ring, which sold the passports for up to 80 000 baht ($2 300).

Some of the nearly 200 travel documents found in a Monday raid on Jafary's home were completely forged, while others had been stolen from tourists and doctored, police said.

The raid also uncovered a laser engraving machine, rolls of ribbon, thin leather for passport covers as well as metal plates and stamps from various countries.

Thousands of passports are reported missing annually in Thailand, where forged documents of every variety can be purchased on the streets.

The flourishing market has helped establish Thailand as a hub for human traffickers and smugglers.

Two Uighur men awaiting trial for planting a deadly bomb in Bangkok last August have also been accused by police of running a crime group that helped illegal migrants obtain counterfeit documents.

The pair are currently being held in a military prison.

In 2014, the spotlight also swung onto the Thai-based trade when two mystery passengers boarded the doomed Malaysia Airlines flight MH370 using European passports stolen in Thailand.

In 2010, Thai authorities took part in an international police sting that saw two Pakistanis and a Thai woman arrested in Thailand for providing fake passports to groups behind global terror attacks.