During his testimony, Pan-thongtae mostly responded to questions with "I don't know", said Viroj Laohaphan, chairman of the AEC's subcommittee investigating the controversial tax-free transaction.

Panthongtae said he did not know much about the deal as his mother's secretary Kanjanapa Honghern handled the proceedings, Viroj said.

The panel was told he could not remember all of the details about the share sale, a source said.

The AEC subcommittee is investigating the sale last January of shares worth Bt73 billion in telecoms giant Shin Corp to the Singaporean government's investment arm. The shares were held by Ample Rich Investments, a paper company registered in the British Virgin Islands that was owned by Panthongtae and his sister Pinthongta. A source said Panthongtae was mostly asked about his relationship with Ample Rich. His testimony confirmed the documents the AEC had obtained.

Panthongtae appeared to be under stress when he entered the room where the questioning took place, a source said.

Kanjanapa is due to testify before the AEC tomorrow, while Pinthongta is set to appear on January 24.

Suvarn Valaisathien, who acted as the spokesman for the Shinawatra family to explain the complex share sale, would be summoned by the AEC to testify on February 1, a source said.

Panthongtae took three short breaks, mostly to smoke, and had a lunch break at noon. Fast food was ordered but he only had a drink.

When the session ended after more than two hours, he appeared run down, but insisted that his family's financial dealings were above board.

"We did everything right," he told reporters.

The tax-free sale caused a public outcry and massive street protests calling for Thaksin to resign. The deteriorating political situation ended in the September military coup.

Panthongtae and his younger sister Paethongtarn, accompanied by their bodyguards, arrived at the AEC's office in the building of the Attorney-General's Office shortly before 11am. They were greeted by more than 100 supporters who offered him flowers and words of encouragement.

The young man wore a yellow jersey, the colour that symbolises respect for His Majesty the King, and a grey jacket.

A brief commotion broke out when Panthongtae and his entourage arrived, as they were dogged by scores of reporters who crowded the entrance. Panthongtae did not answer questions from the reporters, as he and the others had to fight their way through the thick crowd. The newshounds were then pushed away by police and military guards.

On his way out, Panthongtae also received encouragement from supporters, with calls to "fight on" and "don't be scared".

He said he was in contact with his father "from time to time".

He said he and Paethongtarn would accompany their sister Pinthongta when she went to testify to the AEC on January 24.

Other AEC members declined to discuss details of Panthongtae's testimony.

Klanarong Chantik said every word was recorded.

"We are in the process of collecting information and evidence concerning the allegations," he said.

Sak Korsangruang, who is a member of the subcommittee investigating the share sale, said Panthongtae managed to answer most of the panel's questions.

"Everything was fine," he said.

"He could answer nearly all the questions which were basic in nature. It's likely that we won't invite him again to appear unless we need more information," he said.

Viroj said he expected the investigation to be concluded by the end of February.

Bancha Khaengkhan,

Budsarakham Sinlapalavan

The Nation