Lisa Montgomery - the only female inmate on federal death row in the US - has been executed for murder.

She received a lethal injection at a prison in Terre Haute, Indiana, after a last-minute stay of execution was lifted by the US Supreme Court.

The case attracted attention because her lawyers argued she was mentally ill and suffered serious abuse as a child.

The 52-year-old strangled a pregnant woman before cutting out and kidnapping her baby in Missouri in 2004.

Her victim, 23-year-old Bobbie Jo Stinnett, bled to death.

Montgomery is the first female federal inmate to be put to death by the US government in 67 years.

The execution was postponed twice - first by Covid-19, then by a judge - until a Supreme Court ruling cleared the way for it to take place in the early hours of Wednesday.

In a dramatic move late on Monday, a judge in Indiana had halted the scheduled injection until a mental competency hearing could be held.

Her lawyers argued that she had been born brain-damaged and was too mentally ill to be executed.

As a child she was routinely sexually and physically abused by her father and trafficked by her mother, family members said. Her treatment was so violent that it amounted to torture, her lawyers say.

Her defence team believe that at the time of her crime, Montgomery was psychotic and out of touch with reality. That opinion is supported by 41 current and former lawyers as well as human rights groups like the Inter-American Commission on Human Rights.

But her victim's family and friends say the murder committed by Montgomery was so horrific that she deserved to be put to death regardless of her mental health.

She killed 23-year-old Stinnett in Skidmore, Missouri, after befriending the pregnant woman online over a shared love of dogs. After driving to Stinnett's house, Montgomery overpowered the pregnant woman, strangled her with a piece of rope, and cut the baby out of her womb.

Police found Montgomery cradling a new-born girl she claimed to have given birth to the day before. After her story fell apart, she confessed to the killing.

She was found guilty of the crime in 2007. The next day, she was sentenced to death.

Since 2008, Montgomery had been held in a federal prison in Texas for female inmates with special needs, where she has been receiving psychiatric care. Since receiving her execution date, she'd been placed on suicide watch in an isolated cell.

Montgomery's lawyer, Kelley Henry, said her original legal defence was woefully inadequate, and presented few of the details about her abuse, trauma and mental illness.

Before Montgomery's execution, the last woman to be executed by the US government was Bonnie Heady, who died in a gas chamber in Missouri in 1953, according to the Death Penalty Information Center.

Federal executions had been on pause for 17 years before President Donald Trump ordered them to resume earlier last year.