“[The Philippine authorities] now learn that I have been using a phone to contact the outside world ... I guess I will be thrown into an isolation cell,” he said.

His prediction came true so soon that his Philippine lawyer Sheilla San Diego had to go through extra procedures before visiting him on Friday, and found him in the isolation cell.

“He was a bit tired and emotional,” Lisa Tam Sin-man, a core member of the Tang Lung-wai Incident Concern Group, formed by his friends and supporters, said, quoting San Diego.

Tang sent the group a message, asking it to seek help from the British embassy in the Philippines. Tang holds a British National (Overseas) passport, which were granted to Hong Kong residents during colonial rule.

Tam said the group had contacted the embassy, which said it would visit Tang the following week to ensure he was treated humanely.

Tang’s mobile phone has been an important tool — he used it to write the story of his ordeal inside his cell, publishing a book in 2017 which sparked concerns about his case in Hong Kong.

Tang was arrested about a month after arriving in the Philippines and has been languishing behind bars for 18 years. It took 11 years for his case to make it through the legal system and he was found guilty of possession of meth, more commonly known as Ice.

Legislator Paul Tse Wai-chun, who is a lawyer and has been helping Tang for years, said it was understandable that prison management had to act.

“It is now a high-profile case. They have to act according to the rule book,” he said. “I think he is safe.”

The deadline for Tang to submit the records and file a final appeal to the Philippines’ top court was September 5.

Tse said he was arranging a trip to the Philippines before the deadline, for further discussions with San Diego.