OKLAHOMA CITY - After announcing Oklahoma would be returning to the use of lethal injection for executions, state leaders would not comment on how the state was able to obtain a “reliable supply” of the drugs used in the three-drug process.

For the past five years executions had been on hold after three botched executions, leaving the 47 inmates currently on death row waiting to be put to death.

The state’s new lethal injection cocktail will still use the controversial drugs Midazolam and potassium chloride. The use of potassium Chloride has come under scrutiny after it was discovered the state covered up the use of a different chemical to replace potassium chloride in at least one execution after being told it was a suitable substitute.

That inmate, Charles Warner, said his body felt like it was on fire when he was put to death. It was later revealed the state had used potassium acetate in Warner’s execution and was going to use it again in the execution of Richard Glossip, before his execution was halted three times, eventually leading to the 5 year pause on executions statewide.

Midazolam has been exceedingly difficult to get into the state, and early last year officials said it was a large factor in the move away from lethal injection. The effectiveness of the high-powered sedative has been called into question in nearly every state in which it’s currently used.

In 2015, pharmaceutical company Akron asked Oklahoma to return its store of Midazolam to the company to prevent it from being used in executions.

During the Thursday announcement, Attorney General Mike Hunter said the problem in past executions was not with the efficacy of the drugs but “human error.” State leaders now say they will be putting a new, more strict process in place to make sure human error doesn't botch another execution.

“I can assure the state of Oklahoma that we have a system of checks and balances through a protocol that I feel very confident in and establishing a team of individuals to follow those protocols,” Department of Corrections Director Scott Crow said during a press conference Thursday.

When asked where the drugs to resume lethal injection came from, Hunter’s office denied the request because the supply of the three drugs isn't subject to the freedom of information act nor the state's open records laws.

Over the course of the past five years, nitrogen hypoxia has been the alternative execution method the state had been exploring. The method replaces an inmates oxygen supply with nitrogen through the use of an apparatus. Attorney General Mike Hunter says the state will continue working on that method as well, should lethal injection become impossible to carry out or deemed unconstitutional by a court.

Hunter also said the final protocol for lethal injection isn’t finalized yet, including who will be on the teams used during the execution process. Once the protocol is finalized those waiting for executions will have to wait another 150 days before executions can start.