Emergency call records have revealed the confusion that developed among prison staff and emergency call handlers after the execution of convicted murderer Christa Pike went wrong last month in Tennessee.

Pike, 50, who killed Colleen Slemmer alongside her then-boyfriend in 1995, was given two doses of lethal injection on 30 September. Once it became clear that she was not going to die from the dosage, she was taken to hospital.

The confusion resulted in part from an apparent disconnect between prison staff, according to the AP news agency, which first obtained audio of the emergency calls.

This allegedly delayed Pike’s treatment. The BBC has asked the state corrections department for comment.

The department has not yet stated what it thinks went wrong in the attempted execution of Pike. Pike’s legal team has offered the explanation that the pentobarbital chemical, with which she was injected, probably spread under skin rather than reaching her bloodstream in a sufficient quantity to kill her.

Pike has now been discharged from hospital, though in their most recent update on her health, her team cautioned that she faced a “long road to recovery”. It is not clear what treatment, if any, she is receiving now that she is back in prison.

Her case is now in uncharted territory as she is thought to be the only person to have survived an execution attempt by lethal injection.

Slemmer’s mother, who was among those pushing for Pike to be put to death, has branded the failed execution a “mess”.

Pike’s boyfriend at the time of the murder, Tadaryl Shipp, remains in prison, having been spared the death penalty because he was not yet an adult when the crime was committed.