The family of a Hong Kong man imprisoned in the Philippines for more than two decades has appealed to city authorities for help after he remained in custody despite a court in the country recently ruling he had finished serving his sentence.

Tang Lung-wai was arrested in the country in July 2000 for the possession of methamphetamine, also known as Ice, and placed on remand. He was later convicted in 2011 and sentenced to 40 years in prison.

While the court recently ruled that his sentence was now considered served after taking into consideration a good conduct time allowance, Tang’s family said he remained in prison and faced lengthy administrative procedures before he could be deported.

In a decision handed down by the Muntinlupa City Regional Trial Court on July 30, which was also seen by the South China Morning Post, Judge Abraham Joseph Alcantara ordered Tang’s release and transfer to the country’s Bureau of Immigration “for immediate deportation without further proceedings, all in accordance with the law”.

The court ruled that, as of July 5, Tang had technically served 40 years, one month and thirteen days in prison when factoring in his good conduct allowance.

“He has already served the maximum period of detention, making his immediate release warranted,” Alcantara said.

The court also said an inaccuracy in prison records previously showed that Tang had only served 39 years and four months.