A court in southern Vietnam has sentenced a 73-year-old Vietnam-born Australian woman to death for trafficking heroin hidden in bars of soap.

Jackson, Georgia -

A US man who was convicted of killing two college students after confessing to his FBI agent father was executed in Georgia, apologising to the families of both victims before being given a lethal injection.

Andrew Allen Cook, 38, was pronounced dead at 11.22pm on Thursday, about 14 minutes after he was injected with the sedative pentobarbital. He was the first inmate to be executed since the state changed its procedure in July from a three-drug combination to a single dose.

With his last words, he apologised to the families of Grant Patrick Hendrickson, 22, and Michele Lee Cartagena, 19, who were shot several times as they sat in a car at a lake south of Atlanta in January 1995. He said what he did was senseless.

“I'm sorry,” Cook said as he was strapped to a gurney. “I'm not going to ask you to forgive me. I can't even do it myself.”

He also thanked his family for “their support, for being with me and I'm sorry I took so much from you all.”

The Georgia Appeals Court on Wednesday temporarily stayed Cook's execution to consider a challenge to the state's lethal injection procedure. But the Georgia Supreme Court lifted the stay Thursday, and all other appeals were exhausted.

Georgia is one of 33 states with the death penalty, according to the nongovernmental Death Penalty Information Centre in Washington. The Centre says 43 people were executed in the US in 2012.

Cook wasn't charged until more than two years after the killings. He confessed to his father, an FBI agent who ended up testifying at his son's trial.

As a law enforcement officer, John Cook said he was forced to call his supervisor and contacted the Monroe County sheriff.

At the trial, as he walked away from the stand, the distraught father mouthed “I'm sorry” to the victims' families who were sitting on the front row of the courtroom. Several members of both families acknowledged his apology.

The execution of another Georgia inmate is on hold after the US Supreme Court declined to lift a stay of execution. That means Warren Lee Hill likely will not be scheduled for execution before the state's current supply of a lethal injection drug expires next week.

Hill was convicted in the 1990 beating death of a fellow inmate. At the time, Hill was serving a life sentence for killing his girlfriend.

The state says the defence has failed to meet its burden of proving beyond a reasonable doubt that Hill is mentally disabled. - Sapa-AP