As Mr Soodthoop tried to explain to the brother how to obtain a death certificate, the temple’s staff heard a faint knock coming from inside the coffin.
Once it became clear the woman was alive, the temple’s abbot (head of a Buddhist monastery) said the woman should be taken to hospital immediately.
A doctor later confirmed that the woman had been experiencing severe hypoglycaemia – a condition where blood sugar levels get critically low, local reports said.
The doctor ruled out the possibility that she had suffered respiratory failure or cardiac arrest, according to the reports.
The brother said his sibling had been bedridden for the last two years and, as her health deteriorated, she appeared to have stopped breathing on Saturday, according to the temple’s manager.
The family had travelled nearly 500km (311 mile) from the province of Phitsanulok in Thailand for the cremation ceremony.