For Nguyen Thanh Nghi, Thursday’s formal apology came too late. Nghi died in 2013, aged 95. 

Vo Thi Thuong, 94, is the eldest of the six still alive. The rest are 58-73 years old.

Eight people who were detained and placed under investigation in 1979 hailed from the same family. Among them, Nguyen Van Dung, 61, was the first to be acknowledged innocent of the crime, in January 2018.

The same year, Dung filed a lawsuit against the People's Procuracy of Tay Ninh, for a compensation of VND40 billion ($1.7 million), but the Tay Ninh court awarded a meager VND615 million ($27,000).

According to the police records, on the evening of July 26, 1979, a robbery of almost 19 grams of gold took place at a rice mill in Don Thuan’s Bung Binh Hamlet.

The victims reported the case to the police, who opened an investigation and arrested Vo Thi Thuong, then 54 years old, and seven of her family members.

They were charged with theft of private property of citizens without any evidence. After more than 45 months in prison, everyone was released in 1983, the case never went to trial.

In April this year, the authorities admitted to have wrongfully imprisioned Thuong and the remaining six.

One of the immediate relatives of Nghi, who died, went on his behalf to the public ceremony held Thursday at Don Thuan Commune, Trang Bang District, Tay Ninh Province.

At the public ceremony, Nguyen Van Dua, deputy head of the People's Procuracy of Tay Ninh Province, admitted that his office and the procuracy department of Trang Bang District were at fault.

Dua said the investigators did not comply with the law and collect sufficient evidence, resulting in the unjust imprisonment.

He said the jail time of nearly four years was "way too long," and nothing could compensate for 40 years of pain that the victims have suffered.

"On behalf of the leaders of People's Procuracy of Tay Ninh Province and the former procedural body, I apologize most sincerely to the victims," he said.

Nguyen Cong Trung, an authorized spokesperson for the group of seven said they acknowledged the apology and hoped that the authorities would soon send an advance compensation to the victims, because they were facing many difficulties in their lives because of the wrongful imprisonment.

Whether the compensation for the six was decreed by the court or agreed to by the procuracy is yet to be clear.

Trung said: "If only the apology was made while Nghi was still alive."