ATHENS (Reuters) – Greek police on Wednesday arrested a 33-year-old mother who will be charged with intentionally killing her 9-year-old daughter in a case that has shocked the country.

Georgina died in hospital and posthumous toxicology tests showed she had received ketamine, an anesthetic drug often used in animal surgeries, that had not been prescribed by her treating doctors.

The family’s two other young girls had also died in mysterious circumstances in the last three years, prompting the homicides unit to investigate this case.

The mother was arrested in the city of Patras in southern Greece and was being brought to Athens to face a magistrate.

All three siblings died while being treated in hospital. The cause of death of Georgina’s two other sisters remains unexplained and is under investigation.