A man believed to be the main suspect in the bombing of a shrine in Bangkok that killed 20 people has been arrested.

Thailand’s Prime Minister, Prayuth Chan-ocha, said police investigating his country's deadliest ever bombing had detained the man on the border with Cambodia, in Sa Kaeo province.

Mr Prayuth said he was the “main suspect” for the bombing, adding that he was being transferred to Bangkok for questioning.

The Prime Minister said investigators had evidence that several suspects were planning to flee the country but warned against speculating about the arrested man.

"We will know who they are, where they came from, who's behind this," he added. “We have to do a lot of tests, fingerprints. If he is the guy, he is the guy.”

The Bangkok Post reported that authorities believe him to the person highlighted by police in CCTV footage, which showed a man wearing a yellow shirt and appearing to leave a backpack behind at the shrine.

Television footage of the suspect showed a thin man in a baseball cap, sunglasses and with a short moustache being paraded in front of journalists by security forces, who displayed items of evidence found during a search.

Soldiers displayed items seized by the Erawan Shrine bombing suspect arrested near the Cambodian border (EPA)

The suspect has not officially been named but Thai media have been sharing a Chinese passport photo of a man matching his description.

In the passport, he is named Yusufu Mieraili, 25, from Xinjiang. The province is home to China's Uighur Muslim minority, hundreds of whom have been detained and deported by Thailand after attempting to seek asylum there.

The arrest came after security forces detained the first foreign suspect on Saturday following raids in the outskirts of Bangkok.

His identity and nationality have not been confirmed but police requested a Turkish translator to assist in questioning the 28-year-old man, who has been charged with possessing illegal explosives.

A general view taken from a moving train shows bodies covered in white sheets around the Erawan Shrine, central Bangkok, Thailand, 17 August 2015. (EPA)

The bombing of the Erawan Shrine, popular with Hindu and Buddhist worshippers, as well as tourists, killed at least 14 foreigners on 17 August.

Thailand’s military government has claimed it targeted the country’s economy but no group has claimed responsibility.

Speculation has centred on sympathisers of Uighur Muslims, the government’s political opponents, southern ethnic Malay rebels and foreign extremists, among other groups.

Bangkok Bombing Show all 10 1 /10 Bangkok Bombing Bangkok Bombing Bangkok Bombing Motorcycles lie on the street at the scene of a bomb attack near Erawan Shrine, central Bangkok, Thailand, 17 August 2015. An explosion in a busy commercial district in the Thai capital killed a yet unconfirmed number of people. Witnesses said the explosion happened around 7:15 pm (1215 GMT) at the Rajprasong Intersection, a business area famous among tourists and locals for a revered Hindu shrine. EPA Bangkok Bombing Bangkok Bombing A general view taken from a moving train shows bodies covered in white sheets around the Erawan Shrine, central Bangkok, Thailand, 17 August 2015. An explosion in a busy commercial district in the Thai capital killed a yet unconfirmed number of people. Witnesses said the explosion happened around 7:15 pm (1215 GMT) at the Rajprasong Intersection, a business area famous among tourists and locals for a revered Hindu shrine. EPA Bangkok Bombing Bangkok Bombing Officials close off an intersection after an explosion in Bangkok, Monday, Aug. 17, 2015. A large explosion rocked a central Bangkok intersection during the evening rush hour, killing a number of people and injuring others, police said. AP Bangkok Bombing Bangkok Bombing A rescue workers near the scene of an explosion on August 17, 2015 in Bangkok, Thailand. A large explosion believed to be from a bomb has happened in central Bangkok this evening with early reports suggesting 12 people have died and at least 20 more have been injured Getty Bangkok Bombing Bangkok Bombing Motorcycles are strewn about after an explosion in Bangkok, Monday, Aug. 17, 2015. A large explosion rocked a central Bangkok intersection during the evening rush hour, killing a number of people and injuring others, police said AP Bangkok Bombing Bangkok Bombing A Thai soldier (R) looks at the damage after a bomb exploded outside a religious shrine in central Bangkok late on August 17, 2015 killing at least 10 people and wounding scores more. Body parts were scattered across the street after the explosion outside the Erawan Shrine in the downtown Chidlom district of the Thai capital. AFP/Getty Bangkok Bombing Bangkok Bombing A Thai soldier ropes off the scene after a bomb exploded outside a religious shrine in central Bangkok late on August 17, 2015 killing at least 10 people and wounding scores more. Body parts were scattered across the street after the explosion outside the Erawan Shrine in the downtown Chidlom district of the Thai capital. AFP/Getty Bangkok Bombing Bangkok Bombing Thai rescue workers carry an injured person after a bomb exploded outside a religious shrine in central Bangkok late on August 17, 2015 killing at least 10 people and wounding scores more. Body parts were scattered across the street after the explosion outside the Erawan Shrine in the downtown Chidlom district of the Thai capital. AFP/Getty Bangkok Bombing Bangkok Bombing Police chief Somyot Poompanmoung is interviewed by the press on August 17, 2015 in Bangkok, Thailand. A large explosion believed to be from a bomb has happened in central Bangkok on the evening of Tuesday 17th of August, 2015. Early reports suggest 12 people have died and at least 20 more injured. Getty Images Bangkok Bombing Bangkok Bombing Explosive Ordnance Disposal officers enter the Erawan Shrine after an explosion in Bangkok, Monday, Aug. 17, 2015. A large explosion rocked a central Bangkok intersection during the evening rush hour, killing a number of people and injuring others, police said. AP

Thailand drew international outrage last month when it forcibly repatriated more than 100 Uighurs to China.

Police were criticised for the early lack of progress in the investigation, which has accelerated since the weekend, and 22 officers have been transferred from their posts for supposed negligence over illegal immigration.

Arrest warrants were issued for a Thai woman and a foreign man on Monday. The woman, Wanna Suansuant, has contacted authorities and would be interviewed.

Her family told police on Monday she travelled to Turkey to work with her partner and child two to three months ago.