Washington DC - Christa Pike, the convicted killer who survived a botched execution, was walking around her hospital room, though she was mentally "foggy," her lawyer said in an interview broadcast Thursday.

Pike (50) had been considered brain dead following two lethal doses of the drug pentobarbital last Wednesday that failed to kill her.

Doctors had been planning to remove life support on Tuesday when she unexpectedly woke up and started talking, her lawyers have said.

"She is up and walking for the first time today, but just around the room, you know, not very far," lawyer Stephen Ferrell told the BBC.

"She's also somewhat foggy. She can lose her train of thought really easily and forgets where she's going."

"There could be some permanent damage. We don't know that yet," said Ferrell, who has not personally seen Pike or spoken with her, but is getting updates from colleagues who have.

Pike was sentenced to death in Tennessee for the murder of a classmate committed when she was a teenager.

Since the botched execution, her lawyers have repeatedly called on Governor Bill Lee to commute her sentence to life in prison.

Lee has suspended executions in Tennessee pending an independent investigation. Whether the state will eventually attempt to execute Pike again was not known.

"We are very much in uncharted waters," Ferrell said.

Pike is the only inmate to ever survive after being injected with lethal doses of execution drugs, according to the Death Penalty Information Center.

Other cases of botched executions in the US were because the procedure did not go according to plan, though those inmates ultimately died, according to DPI.