Police officers and patients treated by medics after being exposed to chemical when woman who swallowed the poison was found with more with her after being taken to Croydon Hospital

A 'small number of patients' including two Metropolitan Police officers are being treated by medics at a south London hospital after being exposed to a chemical substance. 

Ambulance crews and police had initially rushed to a woman's house in Thornton Heath, Croydon, at 3.46am this morning following reports she had ingested poison.

She was taken to Croydon University Hospital, formerly the Mayday, where she was found to be in possession of a substance believed to be hazardous. Parts of the hospital were sealed off.

The hospital has confirmed that a 'small number of patients' including two police officers were treated - but insisted it was an 'isolated incident'.

Officers and the fire brigade set up safety cordons to ensure no one else was exposed. 

A Met Police spokesman said: 'Police were called at 3.46am by London Ambulance Service to reports of a woman having ingested poison at an address in Thornton Heath.

'The woman was taken to a South London hospital by LAS where she was found to be in possession of a possible hazardous substance. 

'Officers and London Fire Brigade attended Mayday Hospital and safety cordons and closures were established while specialist officers examined the item and safety procedures were enacted.

'Ambulances and emergency vehicles are being given access to the hospital throughout the incident response.

'Two officers were exposed to the substance. They remain at the hospital under observation.'

A spokesperson for Croydon Health Services NHS Trust said: 'Following an incident in Croydon this morning (Thursday 4 April) we have treated a small number of patients, including two police officers for chemical exposure.

'This was an isolated incident and Croydon University Hospital has remained open for patients throughout.'