Ohio executed a convicted killer yesterday through the first US lethal injection using a single drug, a supposedly less painful method than previous executions with three drugs.

Kenneth Biros was pronounced dead at 11:47 a.m. (1647 GMT) yesterday, about 43 minutes after members of the execution team began preparing him by attempting to insert IV needles, at the Southern Ohio Correctional Facility in Lucasville.

The actual execution appeared to last just 10 minutes, about the usual length of time in the past, when Ohio used a three-drug method. The execution team appeared to have trouble finding usable veins, but eventually completed the process after about 30 minutes.

Biros' chest heaved up and down several times and he moved his head a couple of times over a period of about two minutes before his body stopped moving. He apologised for his crime and thanked his friends and family for supporting him.