The use of lethal injections in the US has led to at least nine bungled executions, including one in which the prisoner took 69 minutes to die and another in which the condemned man complained five times: "It don't work," a report by Amnesty International says today.

The report contains a catalogue of botched executions dating from 2000, when lethal injection was adopted by 37 of the 38 US states with the death penalty.

In an execution in Ohio in May last year it took technicians 22 minutes to find a suitable vein in which to inject the lethal combination of three drugs. When the condemned man, Joseph Clark, raised his head to complain that the process was not working, the technicians closed the curtains around his trolley and spent an additional 30 minutes looking for a suitable vein.

An autopsy discovered 19 puncture marks on Clark's corpse.

In a celebrated case in Florida in December last year the condemned man, Angel Nieves Dias, suffered chemical burns along his arms after technicians struggled to find a vein. Reports at the time described Diaz as grimacing in pain.

Such horrific instances have destroyed the main argument for lethal injection - that it offers a relatively painless and humane death, Amnesty says. "A number of executions in the USA have been botched and caused suffering, sometimes prolonged, to the victim."

Amnesty notes that Texas, which operates America's busiest execution chamber, has banned one of the chemicals involved for use in euthanising pets, because it does not effectively mask pain.

The report comes days after an unofficial halt to executions following a supreme court decision to review the lethal injection method. On Tuesday night the appeals court of Texas stayed the impending execution of a Honduran man pending the supreme court's decision.

© 2007 The Guardian