London (CNN)A man is in a critical condition after pouring a "noxious substance" over himself while being sentenced in a London criminal court.
Marc Marshall, 54, who had been convicted on fraud charges, is being treated in hospital for "critical" injuries caused by the incident, which happened around midday Monday.
The emergency services were called to Court 10 of the Inner London Crown Court following reports of a serious assault.
In a statement to CNN, the Metropolitan Police Service said: "Officers, London Ambulance Service and London Air Ambulance attended (and) a male aged in his fifties was found to have doused himself with a noxious substance.
"He has been taken to hospital for treatment of his injuries. His condition is critical."
A female officer was also injured by the substance but since been discharged from hospital, police said.
The London Ambulance Service told CNN in a statement that it took extra precautions at the scene.
"We sent a number of resources to the scene including our hazardous area response team (HART) and an incident response officer," the service said.
Liquids other than drinks and prescription medicines are not allowed in to UK courtrooms. According to regulations, if an individual's drink is opened or in a plastic bottle, they will be asked to drink some to prove it is not harmful.