McALESTER, Oklahoma - Convicted killer Richard Glossip was scheduled to be executed in McAlester on Wednesday, but he has been issued a stay of execution by the governor after it was requested at the last minute by the Oklahoma Department of Corrections after drug protocol questions arose.

About 2:20 p.m., media received word the execution procedures are being delayed due to lack of response from the U.S. Supreme Court on Glossip's petition for another stay of execution. Officials said the delay would continue until the Oklahoma Department of Corrections hears back from the high court.

By 3 p.m., it was announced the execution would go forward as planned after SCOTUS denied Glossip's request for a stay.

At 4 p.m., it was announced Gov. Mary Fallin had granted a 37-day stay of execution as requested by DOC. She specifically noted that DOC attorneys are determining whether potassium acetate is compliant with the court-approved execution procedures.

“Last minute questions were raised today about Oklahoma’s execution protocol and the chemicals used for lethal injection," Fallin said in a statement. “After consulting with the attorney general and the Department of Corrections, I have issued a 37-day stay of execution while the state addresses those questions and ensures it is complying fully with the protocols approved by federal courts.”

Fallin said she wants to know if potassium acetate still is usable according to protocol or if the state could obtain potassium chloride in its place for the execution to move forward. She says it is important to comply fully with standards imposed by federal courts.

DOC says it is unclear on how potassium acetate was even obtained to be used as the third drug in the three-drug protocol for the execution and it needs time to answer those questions.

"We don't know," a DOC official said.

Fallin also addressed the murder victim's family in her statement.

“My sincerest sympathies go out to the Van Treese family, who has waited so long to see justice done,” she said.

9/16/2015 Related Story: Oklahoma Court Issues Stay Of Execution For Richard Glossip

Glossip, 52, was scheduled to be executed Sept. 16 for ordering the beating death of motel owner Barry Van Treece. But hours before his scheduled execution earlier this month, the Oklahoma Court of Criminal Appeals granted Glossip a two-week reprieve after his attorneys claimed they had new evidence that he was innocent.

The appeals court issued a ruling on September 28, saying the new evidence simply expands on theories that were already raised in Glossip's original appeals.

Lawyers for Glossip asked the U.S. Supreme Court to stop his execution Wednesday.

6/29/2015 Related Story: Supreme Court Upholds Oklahoma Use Of Sedative Drug In Executions

A representative for Pope Francis has asked Fallin to commute the death sentence. The letter from Archbishop Carlo Maria Vigano is dated September 19, but was released Wednesday by the governor's office. Vigano, who is Francis' diplomatic representative in the U.S., requested that Fallin commute the death sentence.

The letter says a commutation "would give clearer witness to the value and dignity of every person's life."  A spokesman for Fallin says the governor does not have the authority to grant a commutation.

Glossip claims that he was framed by the actual killer, Justin Sneed, who is serving a life sentence.

Glossip was convicted of ordering the death of Barry Van Treese, the owner of the Best Budget Inn where Glossip worked as the resident manager. Prosecutors allege Glossip masterminded the killing at the motel in Oklahoma City because he was afraid Van Treese was about to fire him for embezzling money and poorly managing the inn.

Sneed, a handyman at the motel, was sentenced to life in prison for fatally beating Van Treese with a baseball bat. In exchange for the life sentence, he agreed to testify against Glossip and was the prosecution's key witness in two separate trials.

If carried out this week, Glossip's execution would be the first in Oklahoma since a sharply divided U.S. Supreme Court upheld the state's three-drug lethal injection formula in June. 

Another death row inmate - Benjamin Cole - is scheduled to be executed on October 7 for the 2002 killing of his 9-month-old daughter despite his attorneys' claims that he is insane and ineligible for the death penalty.

The Associated Press contributed to this report.