US death row inmate still alive after two lethal injections

A woman on death row in the US state of Tennessee remained alive after authorities administered two doses of lethal injection drugs in a failed execution on Wednesday night.

Christa Gail Pike, 50, was due to become the first woman executed in Tennessee in more than 200 years after the US Supreme Court cleared the state to proceed with her execution.

However, Pike remained alive and was later taken to hospital after Tennessee authorities failed to complete the execution.

At 8:26pm local time, witnesses reported that executioners had administered both syringes containing the lethal chemicals but Pike was still breathing.

Pike's lawyers subsequently filed an emergency motion seeking to stop the execution, saying she had not lost consciousness and still had a heartbeat.

They said the curtains separating witnesses from the death chamber had been lowered twice during the procedure.

Authorities appeared to administer two doses of pentobarbital, the drug Tennessee uses for lethal injections. More than 40 minutes after the second dose, witnesses reported that Pike remained alive and could be heard snoring.

Officials escorted media witnesses from the area at about 8:53pm. The Tennessee Department of Correction initially told journalists that it could not immediately explain what had happened.

Authorities later confirmed that they had been unable to complete the execution. Pike was taken to hospital, although her condition was not immediately clear.

The failed execution followed hours of legal battles over whether Tennessee could proceed with putting Pike to death.

Earlier on Wednesday, the US Sixth Circuit Court of Appeals issued a temporary stay of execution in a 2-1 decision as it considered motions from Pike's lawyers and the Tennessee Attorney General's Office.

The state immediately appealed to the US Supreme Court, which later vacated the stay and cleared Tennessee to proceed with the execution.

Justice Sonia Sotomayor dissented from the Supreme Court's decision. Justices Elena Kagan and Ketanji Brown Jackson joined her.

Sotomayor argued that the Sixth Circuit should have been allowed time to consider Pike's pending legal challenge before Tennessee proceeded with the execution.

Pike was sentenced to death for the 1995 killing of 19-year-old Colleen Slemmer in Knoxville.

Prosecutors said Pike, who was 18 at the time, and two others lured Slemmer to an isolated location before torturing and killing her.

Pike was convicted of first-degree murder and sentenced to death in 1996. Her then-boyfriend and co-defendant, Tadaryl Shipp, received a life sentence.

Pike had spent about three decades on death row and was the only woman awaiting execution in Tennessee.

Her lawyers had sought clemency, citing her age at the time of the crime and a history of childhood abuse, trauma and mental illness. Tennessee Governor Bill Lee declined to intervene ahead of the scheduled execution.

The September 30 execution had been scheduled to take place at Riverbend Maximum Security Institution in Nashville.

The failed attempt now leaves Tennessee authorities facing questions over what went wrong and what happens next in Pike's case.