A nationwide manhunt for an outspoken radio commentator accused of threatening the country’s king expanded and has rekindled one of Thailand’s most flammable disputes: the role of its monarchy

Hunt for Thai Radio Personality Grows

Ko Tee Accused of Threatening King Bhumibol

JAMES HOOKWAY

Updated April 14, 2014 7:11 p.m. ET

BANGKOK—A nationwide manhunt for an outspoken radio commentator accused of threatening the country’s king expanded Monday and has rekindled one of Thailand’s most flammable disputes: the role of its monarchy.

Wutthipong Kotchathammakhun, better known as Ko Tee, is among the loudest voices in the populist, pro-government Red Shirt movement.

A onetime factory owner-turned-talk-show host, he has been at the center of street confrontations with conservative demonstrators aiming to overthrow Prime MinisterYingluck Shinawatra and install a royally appointed government, and has repeatedly complained about the way they invoke the name of King Bhumibol Adulyadej to strengthen their cause.

Now, Thailand’s police and armed forces have deployed a dragnet to snare Mr. Wutthipong, 49 years old, after a court issued a warrant for his arrest on the charge of insulting or threatening the monarch, which in Thailand can lead to a prison term of up to 15 years.

“Our detectives are working with local officers and immigration police at border checkpoints to locate Mr. Ko Tee, ” said Police Col. Prasopchoke Prommul, deputy commander of Thailand’s Crime Suppression Division. Officials have searched his home, radio station and other places Mr. Witthipong is known to frequent. “So far, immigration checks show there is no evidence that he has left Thailand. We think he is still here,” Col. Prasopchoke said.

The talk-show host, who has a penchant for Che Guevara -style berets and black combat fatigues, denies saying anything illegal in the video clip that caught Thai authorities’ attention, according to an interview with Vice News.

On Friday, an audio message purportedly recorded by Mr. Wutthipong in Cambodia was uploaded to YouTube. “It might just be a trick to throw police off the scent,” Col. Prasopchoke said.

In some ways, the hunt for Mr. Wutthipong demonstrates how both sides of Thailand’s political divide are striving to be seen as strong defenders of the Thai royal family. Being perceived as anything less than fully committed to the monarchy is a surefire vote-loser in many parts of the country, where King Bhumibol, now 86, is widely revered.

Pictures of the king adorn many homes here, even in northern Thailand, the original home of Ms. Yingluck and her older brother, telecom magnate Thaksin Shinawatra, who transformed Thailand with his own brand of free-spending populist politics before he was ousted in a military coup in 2006. Thailand’s army leaders justified the putsch by claiming Mr. Thaksin was disrespecting and undermining the monarchy, a claim the former leader has repeatedly denied.

More recently, Suthep Thaugsuban, the driving force behind the anti-Shinawatra protest movement, has also accused Mr. Thaksin of plotting to create a republic. Mr. Thaksin steadfastly denies such allegations.

Some Thais, though, are uncomfortable with the way their monarch is repeatedly dragged into the country’s political disputes. Many other members of the Red Shirts, a grass-roots movement that supports the Shinawatra clan, complain that they are characterized by their opponents as being disloyal to the king.

New York-based Human Rights Watch, meanwhile, is among the international organizations criticizing Thailand’s use of lèse-majesté laws to stifle free expression after a sharp rise in prosecutions following the 2006 coup. Independent analysts contend that the more royalist protest leaders such as Mr. Suthep invoke the monarchy, the more long-term damage they risk causing the institution.

“There’s not much they are doing that doesn’t harm the monarchy’s long-term interests,” David Streckfuss, a Thailand-based author and academic, observed recently. Mr. Suthep, for his part, says he is doing what he can to defend the monarchy.

King Bhumibol hasn’t commented publicly on months of chaos that have claimed over 20 lives and prompted Thailand’s courts to annul national elections held in February after protesters occupied polling centers and even government ministries. The impact has also blunted what was once one of Asia’s most promising economies. Thailand’s central bank last month warned that the economy could contract in the first quarter this year compared with the fourth quarter of 2013 because of the conflict as domestic spending shrinks and tourist arrivals fall.

There are fears that the dispute will reignite after Thailand’s New Year holidays finish later this week.

A range of influential voices, including Mr. Thaksin, also have appealed for calm once the holidays pass. But the political temperature instead appears set to climb as Thailand’s anticorruption panel investigates Ms. Yingluck’s alleged mishandling of a multibillion-dollar rice subsidy.

She denies wrongdoing, but if she is found guilty she will undergo an impeachment trial in Thailand’s Senate.

Thailand’s Constitutional Court is also set to rule on whether Ms. Yingluck should be removed from office after another court ruled she illegally dismissed the country’s former national security adviser.