ATLANTA (Reuters) - Georgia officials on Thursday continued to fight a rare order allowing the execution of a man convicted in a triple killing to be videotaped.

Andrew Grant DeYoung, 37, is set to be put to death by lethal injection at 7 p.m. for fatally stabbing his parents and his 14-year-old sister in their suburban Atlanta home in 1993.

The execution initially was scheduled for Wednesday night, but the Georgia Department of Corrections postponed it for unspecified reasons.

DeYoung's execution could be the first one videotaped in the U.S. since 1992, saidRichard Dieter, executive director of the Death Penalty Information Center.

A judge this week ordered the videotaping of DeYoung's lethal injection after lawyers for another death row inmate raised concerns about Georgia's lethal injection process.

The Georgia Supreme Court upheld the order, citing procedural errors in the state's appeal.

Early on Thursday, the state asked the original judge to reconsider her order.

In their motion, Georgia attorneys said videotaping would interfere with security measures surrounding the execution.

The state also took issue with the judge's decision to allow experts to be present during the execution to witness DeYoung's "physiological responses" to the drugs, saying the order conflicts with state law regarding who may witness an execution.

Attorneys for death row inmates have argued that pentobarbital, one of the three drugs Georgia uses in lethal injections, causes "needless suffering."

Georgia first used pentobarbital, a sedative often used to euthanize animals, for the June 23 execution of Roy Blankenship.

A reporter who witnessed that execution said Blankenship "jerked his head several times throughout the procedure and muttered after the pentobarbital was injected into his veins," according to court documents filed by DeYoung's attorneys.

Attorneys for the state said the execution protocol requires a nurse and warden to examine the inmate after pentobarbital is administered to make sure he is unconscious before administering the second drug, pancuronium bromide.

So far the state and federal courts have refused to issue DeYoung a stay of execution.

Dieter of the Death Penalty Information Center said videotaping the execution is a good idea.

The only other instance of videotaping he is aware of occurred in California in 1992 as part of a challenge against the gas chamber. He cannot say whether prisons videotape executions for their own use.

"There are a lot of challenges with what's happening with lethal injections," he said. "Basically it's an experiment going on in each state."

"I do think having advanced scientific record of them is certainly appropriate."

(Editing by Colleen Jenkins and Greg McCune)