The Appeal Court has upheld a three-year jail sentence, without suspension, on former deputy finance minister Benja Louischareon and three ministry officials in the Shin share sale tax case.
They were ruled guilty of malfeasance in 2016 under Section 157 of the Criminal Code.
The court also upheld a two-year jail term on Pranee Vejjapruekpitak for collaborating. Ms Pranee was close to the secretary of Khunying Potjaman na Pombejra, the ex-wife of former prime minister Thaksin Shinawatra.
After the ruling, they sought bail pending an appeal but the court had yet to make a decision on Thursday. They were therefore brought to be detained at Bangkok Remand Prison and the Central Women Correctional Institute pending the court's decision.
Since the Appeal Court upheld the ruling and the sentences, the defendants cannot appeal on facts -- whether they are guilty or not guilty -- unless a collaborating judge in the case or the attorney-general endorses their appeal.
The ruling was read at the Supreme Court's Criminal Division for Persons Holding Political Positions in Bangkok on Thursday.
Mrs Benja was formerly a deputy director-general of the Revenue Department before she became a deputy finance minister during the Yingluck Shinawatra government.
The three former Finance Ministry officials are: Ms Chamras Yamsoithong, an ex-director of the Finance Ministry's Legal Office, Ms Moreerat Boonyasiri and Mr Krit Vipulanusart.
In late 2015, the National Anti-Corruption Commission (NACC) filed charges against the five, accusing them of helping two of Thaksin's children -- Panthongtae and Pinthongta -- evade taxes and receive benefits they were not entitled to.
The case centred around one of the transactions leading to the sale Shin Corporation Plc by the Shinawatra family to Temasek of Singapore in early 2006.
Mr Panthongtae and Mrs Pinthongta each bought 164.6 million Shin shares in 2006 at one baht each. The market price at the time was 49.25 baht.
The NACC accused them of failing to pay the tax on the price difference totalling 7.9 billion baht, causing damage to state.
The Supreme Court's Criminal Division for Persons Holding Political Positions ruled them guilty of malfeasance in July 2016 and handed down a three-year jail term without suspension on Mrs Benja and the three officials. Ms Pranee, as the collaborator, got two-thirds of the penalty, or two years.
The five defendants appealed and were allowed bail for a surety of 300,000 baht each.
The Appeal Court on Thursday rejected all arguments raised by the defendants -- whether the plaintiff had the jurisdiction, whether the damage was realised and whether they deserve a light penalty or suspension.
"The five defendants committed the offence without regards to the damage and credibility of the country's tax collection," the court said.
"In their bid to seek suspension of the punishments, they couldn't claim the damage was not realised because the Supreme Court's Criminal Division for Persons Holding Political Positions had already ordered the seizure of all related assets. Nor could they argue the central tax court had lifted the tax evaluation in this case."
The case dated back to 2005, when Ms Pranee sent a letter to the Revenue Department, asking whether Mr Panthongtae and Ms Pinthongta would have to pay tax if they bought Shin shares from Ample Rich Investment Limited.
The letter explained Ample Rich, registered in the British Virgin Islands, bought 32.9 million Shin shares at 10-baht par in 1999. Shin Corp later reduced its par price to one baht, resulting in Ample Rich's holding increasing to 329.2 million shares.
Mrs Benja, who was acting director-general of the Revenue Department at the time, replied Ms Pranee in a letter dated Sept 21, 2005.
"If Mr Panthongtae and Ms Pinthongta buy Shin shares at a below-market price, it shall be considered buying a product cheaply, which depends on the consent between the buyer and the seller under Section 453 of the Civil and Commerce Code," the letter said.
"The price difference is therefore not taxable income under Section 39 of the Tax Code," it concluded.
The letter also stated Ample Rich's sale of the shares to the pair, who were its directors, at one baht each was not considered the benefits of employees or directors, who receive free or cheap shares of the companies they work for, under the tax committee's No.28/2558 ruling because "Shin shares are an asset or goods held by Ample Rich. They are not the shares issued by Ample Rich itself".
The Asset Scrutiny Committee, a body set up after the 2006 military coup, later begged to differ. It found the sale of shares was different from that of other assets as they were securities which came under the Securities and Securities Market Act. They were not ordinary products that came under the Civil Code.
It therefore forwarded the case to the attorney-general to take legal action against the five persons but the attorney-general decided not to prosecute them.
The NAAC picked up the case and filed charges against them without going through the attorney-general in late 2015. The the Supreme Court's Criminal Division for Persons Holding Political Positions found them guilty as charged in 2016.