Thanh Tung's family is lodging a complaint with Hanoi medical authorities in relation to an incident in late 2014, when the musician was under the care of the French Hospital of Hanoi, Vietnam for a slight fever. After an initial medical examination, doctors said there was no serious problem, wanted to keep Tung overnight for observation.

When Nguyen Thanh Thong, the musician’s son, came back the following morning, he was informed his father was in critical condition and might not recover.

Thong said Dr Nguyen Ngoc Tho, head of the hospital’s Positive Care Ward, "told me that my father might not be able to recover and that we should prepare for the worst situation. I found it hard to understand such a sudden change overnight."

He sought Tho’s approval to move his father to Bach Mai Hospital, but was refused because there was no ambulance available for transportation. Thong alleges Tho told him the musician should remain under the hospital's care.

“When I tried to persuade him, he did not agree," Thong alleged. "We quarrelled. He shouted at me and threatened to record our conversation. I felt helpless."

Thong sought the help of influential friends, who managed to secure Tung's transfer to Bach Mai Hospital.

He said doctors at Bach Mai Hospital told him his father had rice gruel in his lungs, possible inhaled while he was being fed by nursing staff at the French Hospital of Hanoi, Vietnam, which triggered a critical response.

Tung recovered after a week's treatment at Bach Mai Hospital and was released in good health.

His family felt aggrieved by his treatment at French Hospital of Hanoi, Vietnam and reported the incident to the hospital's leaders.

Tho has issued an apology to the family.

“I’m sorry for my impolite behaviour and for losing my temper," he said.

Thong said he was not satisfied with the response of the French Hospital of Hanoi, Vietnam, nor Tho's apology, and will take his complaint to the municipal Department of Health.