A female Vietnamese prisoner on death row for drug trafficking allegedly made herself pregnant to escape the penalty.

Nguyen Thi Hue, 42, is expected to give birth in April, investigators and prosecutors told Thanh Nien News on Tuesday (Feb 16).

Hue, who was arrested for drug trafficking in the northern province of Quang Ninh in 2012, was found guilty and sentenced to death in 2014.

While in prison, Hue allegedly paid a 27-year-old male inmate, Nguyen Tuan Hung, 50 million Vietnamese dong (S$3,100) in August last year.

Hung then collected his semen in a plastic bag and passed it to Hue - along with a syringe - on two separate occasions. Hue succeeded in getting pregnant after inseminating herself, investigators said.

Four officers at the local prison where Hue is being housed have been suspended for alleged negligence.

Under Vietnamese law, a pregnant woman or a mother whose child is less than three years old cannot be sentenced to death. Hue is likely to have her sentence reduced to life imprisonment.

It is not the first time a female prisoner resorted to making herself pregnant to escape the death penalty, Thanh Nien News reported.

In March 2007, Nguyen Thi Oanh, who was also on death row for drug trafficking, gave birth to a boy after she had sex with a male inmate.

The two correction officers from the prison in Hoa Binh Province who allowed her to have sex were jailed.