Thai former Prime Minister Thaksin arrives in Bangkok in anticipation of a pivotal court appearance.

Thaksin Shinawatra, the controversial former Prime Minister of Thailand, returned to Bangkok on Monday afternoon, sparking a wave of public suspicion and allegations of special treatment. The 76-year-old returned by private jet, almost two decades after he was ousted in a military coup and went into exile.

Thaksin's sentence for corruption and abuse of power was handed down after his return in August 2023. Initially, he was sentenced to eight years in prison, but he never spent a night in a cell. Instead, he was whisked from a detention center to a private room in Bangkok's Police General Hospital almost immediately after his sentencing. His sentence was later reduced to one year through a royal pardon, and he was released in February 2024 as part of an early release scheme for elderly prisoners.

The investigation regarding the correct execution of Thaksin's prison sentence was conducted by the Supreme Court of Thailand. The results of this investigation are due on Tuesday, and the ruling may potentially see Thaksin jailed once again.

The Shinawatra dynasty, long a key foe of Thailand's pro-military, pro-royalty elite, has been facing a series of legal and political setbacks. The ousting of the Pheu Thai Party, the Shinawatra dynasty's party, from office last week is a potential further blow to their momentum. The party, led by Thaksin's daughter, Prime Minister Paetongtarn Shinawatra, was sacked by judges who found she breached ministerial ethics during a border row with Cambodia.

Thaksin has pledged to attend the court date in person, and his return to Bangkok, timed with the formation of a new Pheu Thai government, has fuelled speculation of a backroom deal. However, Anutin Charnvirakul, a former ally of Pheu Thai, who is now the leader of Thailand's government, has pledged that his administration would let the law "take its course".

The Shinawatra clan's momentum is flagging, but their influence remains significant. The results of the Supreme Court investigation into Thaksin's case may still potentially see him jailed, despite his early release. The investigation has been ongoing since April, with the Supreme Court's Criminal Division for Persons Holding Political Position probing prison and medical officials to determine if the sentence was properly served.

Meanwhile, Anutin officially took office on Sunday, marking a significant shift in Thailand's political landscape. The Pheu Thai Party, which had monopolised Thailand's top office since the 2023 elections, has been replaced by a new coalition led by Anutin. It remains to be seen how this change will impact the ongoing investigation into Thaksin's case and the future of the Shinawatra dynasty.