The governor of the US state of Oklahoma on Wednesday issued a last-minute stay of execution for death row inmate Richard Glossip over a drug used in the lethal injection procedure.

Governor Mary Fallin issued a 37-day stay, saying the state needed time to address questions about the use of potassium acetate, to ensure "it is complying fully with the protocols approved by federal courts."

Fallin's order came after the Supreme Court had rejected an appeal from Glossip's lawyers for a last-minute stay.