Oklahoma's highest court put an indefinite hold on three scheduled executions on Friday so state officials can investigate how the wrong drug got delivered for a lethal injection earlier in the week.
The state attorney general's office requested the delay while officials investigate the mix-up and look to possibly change the execution protocol.
The switch was discovered Wednesday afternoon, just a few hours before Richard Glossip was set to be executed for the 1997 murder of his boss over the objections of Pope Francis and celebrity supporters who say he is innocent.
Gov. Mary Fallin's office said the pharmacist used by the prison couldn't get the third chemical requested for in the three-drug injection — a heart-stopping dose of potassium chloride. Instead, the pharmacist substituted potassium acetate without notifying prison officials.
They arrived at the prison in a sealed package that was opened in the early afternoon, according to Fallin's office, contradicting her earlier statement that the mistake was uncovered in mid-morning.
Officials scrambled to get potassium chloride so they could carry out the execution but couldn't find any, and Fallin signed a stay of execution and ordered a review of procedures.
It was the fourth stay of execution for Glossip, who had been waiting in a holding cell in his boxers while officials tried to figure out what to do, according to his attorneys. He told his lawyer the situation was "crazy."
Glossip was convicted of orchestrating the murder of motel owner Barry Van Treese. The man who fatally bludgeoned the victim testified against Glossip and got life.
Glossip's supporters include actress Susan Sarandon, Virgin chief Richard Branson and football coach Barry Switzer.
This article originally appeared on NBCNews.com.