An inquiry is under way after a child abusing father committed suicide by drinking poison in the dock at Isleworth Crown Court.

It is thought to be the first time a defendant has committed suicide in an English court.

Ratnasabapathy Anandakumar, 40, was being retried over charges of subjecting his three-month-old daughter to prolonged abuse, but was found guilty of assault on June 28.

Police liaison officer Mark Hillen at Isleworth Crown Court, said: "He was taken to the accident and emergency department at West Middlesex Hospital. They would have tried to save his life, but I assume the poison he took was too strong."

Mr Anandakumar had not been remanded in custody and was therefore able to walk into the dock with his drink laced with what is believed to be cyanide. He died an hour-and-half later in hospital.

A review into the role of security guards in the court is underway, but officers at the court believe that searching defendants can only achieve so much, and the only way to prevent this happening again is to ban anyone taking drinks into court.

Officer Hillen said: "As the verdict was announced he took the bottle out. He hadn't actually been sentenced, but that's academic now.

"He was quite a quiet Sri-Lanken chap, and very small, about 5ft.

"It happened quite late in the day and it's not uncommon to see people leaving in ambulances, but everyone was very shocked to hear the next day that he was dead."

Mr Anandakumar, from Kingshill Avenue in Northolt, had already served two years of a five-year sentence, but was granted a retrial to take into account his mental condition.

The injuries to his daughter were so severe that she was left partially blind, epileptic and quadriplegic.

As the sentence was about to be read out, Anandakumar took out a coke bottle filled with a clear liquid and drank it before security could stop him.

Her Majesty's Court Service are investigating the matter and co-operating with the police and the coroner.

Zul Mirza, emergency consultant at West Mid, said: "The most frequent overdoses that we see and are normally paracetamol or alcohol, but with any case we provide supportive treatment by checking the airways and monitoring the blood pressure and making sure they get enough oxygen and fluids via an intravenous drip.

"Blood samples are also sent to the lab for analysis."