SINGAPORE - An Australian man died on board a SilkAir flight from Australia to Singapore early Tuesday (Aug 16) morning.

The airline confirmed that a passenger died en route from Darwin on Flight MI804, which landed at Changi Airport at 5.45am that day.

The Straits Times understands that the man is Mr Graham Francis, 71, who was travelling with his wife Judy, on their way to a family holiday in Phuket.

His son Ronald, 45, told The Straits Times that his father appeared to have suffered a heart attack in the plane's toilet.

He said the toilet door was taken off to get Mr Francis out and the area blocked off. A doctor and a nurse, who were fellow passengers, tried to resuscitate him, but to no avail. Cabin crew were also among those who attended to Mr Francis.

"He was a great guy, very kind and very giving," Ronald said. "He was a very active man who always liked to move and travel, even in retirement."

Ronald added that his father had had a heart operation about 20 years ago to replace a faulty valve. A doctor had said at a check-up six months ago that everything was fine.

"He was very well thought of by many people and I know he will be missed," he added.

Ronald, his Japanese wife, their two young children and her parents were on their way to the airport in Osaka, Japan, when they heard the news.

They were heading to Phuket for the holiday, as was Ms Cheryl King, Mr Francis' ex-wife and Ronald's mother, who was due to fly from Melbourne.

Ms King told The Straits Times: "It's such a sad thing to happen.

"It's the saddest 24 hours for a very long time. Even though he's my ex-husband, he's a very, very nice man and we're all very good friends."

Mrs Francis told ST that SilkAir staff "went above and beyond their duty to help and assist me during and for many days after". She added that they were "absolutely wonderful and supportive".

Mr Francis was cremated in Singapore on Wednesday evening. His ashes will be brought back to Australia on Thursday (Aug 18).