Mr Armstrong had been living on the island of Koh Tao where he had been taking a diving course.

BBC: Helen Armstrong-Bland and Tom Armstrong

Mr Armstrong had been in Thailand since last April and was living on the island of Koh Tao for a diving course.

BBC: Tom Armstrong

Tom Armstrong has been in Thailand since last April and had been living on the island of Koh Tao for a diving course.

BBC: Tom Armstrong

Mr Armstrong, who is 6ft 2ins tall, has fair hair and an occasional short red beard, had been in Thailand since last April and had been on a diving course on the island of Koh Tao.

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