Shock as murder convict took nearly two hours to die during execution

Arizona, USA: Convicted murderer Joseph Wood, 55, writhed in agony after being administered a lethal injection in Arizona, USA.

An Arizona death row inmate took almost two hours to die after being administered a lethal injection following a denial for a stay of execution over concerns about the new drugs.

For more than an hour convicted killer Joseph Wood writhed in agony while strapped to the gurney as his lawyers watched his "gasping and snorting" as he died.

So concerned by his state of distress his attorneys applied for an emergency stay of execution as he lay on the bed.

"We respectfully request that this court stop the execution and require that the Department of Corrections use the lifesaving provisions required in its protocol," the lawyers said.

"He is still alive.

"This execution has violated Mr Wood's eighth amendment right to be executed in the absence of cruel and unusual punishment," the court filing added.

The state attorney general announced Wood, 55, had died before the court could rule on the motion.

The execution began at 1.52pm yesterday and ended at 3.49pm.

Wood was convicted of murdering his estranged girlfriend and her father in 1989.

The botched execution is the latest to cause controversy in America.

Over the past several months America’s death row units have found it increasingly difficult to obtain the deadly injections because of a European-led boycott on such sales.

The controversy surrounding the use of such methods has recently gained momentum after European manufacturers, including the Denmark-based maker of pentobarbital, banned US prisons from using their drugs for executions.

In Oklahoma in April witnesses watched as convicted murderer and rapist Clayton Lockett convulsed, clenched his teeth and struggled to talk on the execution before officials moved in to block their view.

The 38-year-old killer's death was the first time the state had used a new, three-drug lethal cocktail.

Lockett died of a heart attack 43 minutes after he was initially injected.

The incident came after Ohio killer Dennis McGuire suffered respiratory problems for more than 10 minutes during his execution.

Currently 32 of the 50 states in America have the death penalty.

All rely on the lethal injection method but fewer than 12 regularly carry out executions.

Texas is the state with the highest number of prison executions.