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

Governor Mary Fallin issued a 37-day stay, saying that 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."

The execution was thus postponed until November 6.

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

Her executive order explains that potassium acetate was to be used as the third drug in the lethal injection cocktail. The stay was granted to allow time to check on the viability of the substitute drug, "and/or obtain potassium chloride."