A Hong Kong tourist fell from a cliff and died in a national park in the popular Thai destination of Chiang Mai, after his companions reportedly left him alone temporarily as he felt unwell on a hike. The 61-year-old man, surnamed Kwan, was hiking with a group of friends in Op Khan National Park in Samoeng district on Friday when the tragedy happened, according to the Universal Daily News , a Chinese-language newspaper in Thailand. The report cited Kwan's friends as saying he suffered from heart disease and experienced difficulty breathing during the hike. He took a rest and asked his friends to carry on, which they did. After they had finished visiting some scenic spots and returned to the place where Kwan had stopped, they were unable to find him. The group searched and later found his body lying at the bottom of a cliff. Police arrived after the friends made a report. Police believed he fell from a height of 30 metres when he suffered a heart attack. A preliminary postmortem examination found the main cause of death was blocked blood circulation at the neck, the newspaper said. Hong Kong's Immigration Department confirmed it had received a request for help after a Hongkonger died after falling off a cliff in Chiang Mai, but declined to give his name, citing privacy. "The Immigration Department immediately contacted the family members of the deceased, the Office of the Commissioner of the Ministry of Foreign Affairs … and the consulate general … in Chiang Mai, and rendered practical assistance," a department spokesman said.