US murderer Christa Pike discharged from hospital 10 days after failed execution

US death row inmate Christa Pike has been discharged from hospital following her botched execution at the end of last month, her lawyers have said.

Pike, 50, has been sent back to the prison where she has spent the last 30 years and is continuing to receive medical care, according to a statement from her lawyers on Saturday.

She survived two lethal injections of the drug pentobarbital on 30 September, which left her in a critical condition.

Pike regained consciousness earlier this week and began speaking - stunning experts, medical staff and her lawyers.

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.

Pike's lawyers said in their statement that she was "grateful to the first responders and her medical team for their care in these extraordinary circumstances".

It is unclear what medical care Pike is receiving now that she is back in prison but her lawyers previously said she faced a "long road to recovery".

The Tennessee Department of Correction is yet to say why the execution did not go as planned, though it has defended the method it used.

At a court hearing on Wednesday, Tennessee Assistant Attorney General Will Ayers told the judge he did not know whether the state intends to try to execute her again.

The judge ordered the state to preserve all evidence related to the failed injections. That evidence could lay the groundwork for a future lawsuit against the state.

Pike was 18 when she and her then-boyfriend, Tadaryl Shipp, beat, tortured and killed 19-year-old Colleen Slemmer, whom they had met at a job training camp for low-income young people.

Shipp was spared the death penalty because he was not legally an adult when the crime was committed. He remains in prison.

Pike was the first woman scheduled to be executed in the state of Tennessee in over 200 years.

Her lawyers have spent decades appealing her case. In the days leading up to her scheduled execution, both the US Supreme Court and Tennessee Governor Bill Lee declined to block the execution.

Since it failed, Pike's lawyers have renewed their calls for her sentence to be commuted to life in prison without the possibility of parole.

Pike lost consciousness and was taken to a local hospital following her botched execution. Her legal team believed for days that she was brain dead and expected her to be taken off life support at any moment.

Pike eventually woke up and began talking again on Tuesday - her lawyer Randy Spivey said her first words were "Where am I?" and "Who are you?"

At a press conference on Wednesday, her lawyers said she was shackled to the bed and suffering from pneumonia and significant swelling on her arms, while also being unable to swallow.

"We don't know the toll all of this will take" Spivey said of her mental health, adding that Pike felt "angry and confused".