Police in Thailand say they will formally summon the country's most senior-ranking monk, after he refused to answer direct questions about his luxury 1958 Mercedes-Benz.

Key points: Monk reportedly transferred ownership of luxury car after scandal broke

Monk reportedly transferred ownership of luxury car after scandal broke Police have warned Somdet Chuang an arrest warrant could be issued

Police have warned Somdet Chuang an arrest warrant could be issued Somdet Chuang is linked to a popular brand of Thai Buddhism that encourages material wealth

The car was part of an extensive museum kept at Wat Paknam temple in Bangkok, but has now been seized by police investigating possible tax evasion.

Acting Supreme Patriarch Somdet Phra Maha Ratchamangalacharn, better known as Somdet Chuang, reportedly transferred ownership of the luxury vehicle to another monk after the scandal broke.

Somdet Chuang is Thailand's most senior-ranking monk. ( Supplied )

Officers from Thailand's Department of Special Investigations met with Somdet Chuang and his lawyer on March 16.

The police officers brought gifts of candles and incense as a show of respect to the religious leader.

Staff at the temple also asked police to hand over their mobile phones before the meeting.

However, investigators were not pleased when Somdet Chuang refused to answer their inquiries directly, instead insisting written questions be sent to his lawyer.

"This is a criminal case ... [but] he didn't allow us to question him," Justice Minister General Paiboon Koomchaya said.

"If he doesn't show up after the summons, then we have to issue the arrest warrant," General Paiboon told local media.

Somdet Chuang has previously said the 1958 Mercedes Benz 300D Cabriolet — reportedly one of only 65 ever made — was a gift from a follower.

The ABC attended a Dhammakaya ordination ceremony. ( ABC News: Liam Cochrane )

Temples of wealth in contrast to 'simple living'

Commentators said the scandal reflected Thailand's deeply divided politics, as well as the struggle between traditional values and modern consumerism.

Somdet Chuang is linked to a popular branch of Thai Buddhism called Dhammakaya, which teaches meditation but also encourages material wealth.

At a recent ordination ceremony attended by the ABC, an announcer offered a public blessing to Dhammakaya followers that contrasted with Buddhism's usual emphasis on simple living.

"May I be replete with great and inexhaustible wealth every life time," the announcer said, as foreign monks received their robes.

Dhammakaya has branches across the world, including in Sydney.

Followers of Dhammakaya are taught meditation but are also encouraged to build material wealth. ( ABC News: Liam Cochrane )

The temple's handling of donations has been a long-running issue in Thailand, with Dhammakaya's abbot investigated for embezzlement in 1999.

"I saw that this community is just a little pump, siphoning money into huge accounts unknown," said Mano Laohavanich, a former senior member of Dhammakaya who left in the 1980s and has since become one it's most vocal critics.

Followers of Dhammakaya reject the claims, saying their temple focused on meditation and that generosity was a fundamental part of Buddhism.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 6 minutes 39 seconds 6 m Tax scandal rocks Thailand's religious institutions and exposes Thai monks' growing penchant for mat

"The temple has taught me the true meaning of life ... inner happiness, which can be achieved through meditation," Suwat Attichanagorn, an Assistant Professor at Chulalongkorn University's Faculty of Engineering, said.

"The merit that we get from giving is prosperity or material wealth."

The link between the Dhammakaya sect and Thailand's most senior monk is strong.

It was Somdet Chuang who ordained the leader of Dhammakaya — known as Dhammachaiyo — and Dhammakaya reportedly donated more than $1 million to build the temple complex now run by Somdet Chuang.

"There's contention because he [Somdet Chuang] is very close to Dhammakaya and Dhammakaya is a movement considered by many people in this country as endangering the teaching of the Buddha," scholar Sulak Sivaraksa said.

"[It's] teaching people that to be powerful is good, to have money is good, the more you spend money on the Dhammakaya you can even see the Buddha — and you can even live forever."

Dhammakaya is also associated with former prime minister Thaksin Shinawatra, who fled Thailand in 2008 ( ABC News: Liam Cochrane )

'If you wear yellow robes, it covers everything'

Dhammakaya is also associated with former prime minister Thaksin Shinawatra, who fled Thailand in 2008, just before being found guilty of abuse of power.

"Thaksin supports the new demonic religion — he'll do anything to make money and Dhammakaya do anything to make money, so they're all together," Mr Sivaraksa said.

Mr Shinawatra remains a divisive figure in Thailand — loved by many rural Thais for introducing cheap health care and farm subsidies but loathed by others, including many of Bangkok's elite.

The schism is represented visually by the red shirts worn by Mr Shinawatra's supporters and the yellow shirts worn by his opponents.

The prospect of Mr Shinawatra's return sparked deadly political protests, which eventually led to the military overthrowing his sister — then prime minister Yingluck Shinawatra — in a coup in 2014.

The military government has made fighting corruption one of its main goals.

But despite the luxury cars and scandals, Mr Sivaraksa said there was still little oversight for the finances of Thailand's religious institutions.

"If you wear yellow robes, it covers everything," Mr Sivaraksa said.