BANGKOK • A new scheme that would allow Thai police to intercept telephone calls in national security cases has been put forward to Cabinet for approval, police said yesterday, a move that has alarmed rights groups.

The move aims to give police the authority to wiretap communication by amending a 1934 Criminal Procedure Code and is the latest security measure rolled out by the military government which took power following a 2014 coup.

"A Cabinet meeting agreed in principle to allow tapping of telephone calls for criminal cases," police spokesman Dechnarong Sutthicharnbancha, told Reuters, adding that there were still several steps until the law is approved.

Police seeking to intercept calls will have to ask court permission, said a senior police officer involved in amending the law, who declined to be named because he was not authorised to speak to media.

Cases that would qualify include criminal, national security, royal insult and transnational crime cases but not political cases, he said.

Mr Sunai Phasuk, Thailand researcher at Human Rights Watch, called the idea disturbing.

"The idea is very disturbing, given Thai authorities' reckless and arbitrary use of security charges," Mr Sunai told Reuters. "Steps will have to be established to prevent the misuse of surveillance."

Mr Dechnarong said the law would not be misused and needed court approval before calls can be tapped.

Thailand's telecom regulator on Tuesday approved in principle a requirement that foreign visitors use and register special SIM cards for their phones that can be tracked by authorities in the interests of national security.

Since taking power in 2014, the military has curbed freedom of expression and has made full use of Article 44 of the interim Constitution - often dubbed the "dictator's law" by its critics - which gives the military sweeping powers to silence opposition.

Prime Minister Prayut Chan-o- cha, who is also head of the junta, said on Wednesday that Article 44 would remain in place until a new, military-backed Constitution is endorsed in October or November.

Criticising the monarchy is a serious criminal offence in Thailand where Article 112 of the Penal Code states that "whoever defames, insults or threatens the king, queen, heir-apparent or regent" can be punished with up to 15 years in prison.

Mr Prayut has made royal insult cases a priority since taking power. Rights groups have said the military is using lese-majeste laws as a political tool.

REUTERS