The interim prime minister hand-picked by Thailand's military commanders is expected to be formally announced and sworn-in Sunday after the country's king gives his approval, television editors said Saturday.

The choice is expected to be former army commander Surayud Chulanont. But so far, Surayud has refused to comment on his possible appointment and the military council has yet to release a name.

"We have been told to prepare to broadcast the swearing in ceremony scheduled for 5 p.m.," a deputy editor of the military-run, Channel 5 station said, speaking on condition of anonymity. A reporter at a second station, iTV, confirmed the planned announcement, but also requested anonymity. Neither was authorized to speak publicly.

CountryWatch: Thailand

Col. Akara Thiprot, a spokesman for the ruling military council, only would say that an interim constitution under which the country will be governed for the next year and possibly the name of the chosen leader has been sent to the king for endorsement.

After days of rushed activity by the new rulers, Bangkok lapsed into a weekend lull, broken only when a taxi cab rammed into one of the tanks which have been deployed in the capital since the Sept. 19 coup.

The crumpled, purple taxi had the words "democracy destroyed" and "suicide" written on it with black spray paint, but Akara downplayed the incident.

"I'm not sure if he was sleeping or drunk. He was an elderly man, more than 60 years old," Akara said of the cab driver who was taken to a nearby hospital with serious injuries. A soldier suffered minor injuries.

The council has hinted that it had chosen Surayud, a respected, 63-year-old retired officer, to lead the new government.

The expected appointment of Surayud was likely to be welcomed by many Thais. Over a 40-year career in the military, Surayud garnered a reputation for effectiveness, tact and incorruptibility.

Coup leaders also announced Saturday they were expanding their corruption investigation to tax evasion by cabinet ministers as well as bribery in government and state enterprise.

Critics of ousted Prime Minister Thaksin Shinawatra have charged that he used his official position to enrich himself and his associates. The military has cited corruption as one of the reasons for the takeover and gave more power to the anti-corruption committee.

The former prime minister's family was one of the wealthiest in Southeast Asia even before he came into office in 2001. Calls for his resignation grew, however, after he sold the centerpiece of his business empire — telecoms giant Shin Corp. — to Singapore's state investment company, Temasek Holdings, for a tax-free $1.9 billion.

Meanwhile, a spokesman for the party of Thaksin had called a colleague Friday morning from London to say he has no current plans to return to Thailand.

Thai Rak Thai party spokesman Sita Divari said Thaksin told deputy party leader Sudarat Keyuraphan of his intentions not to return in the near future, and also repeated his request that party members cooperate fully with the ruling military.