Britain’s Health Security Agency is continuing to investigate a cluster of Legionnaires’ disease cases linked to North and SW London.

The public health body is working to discover whether the cases are linked and to establish their possible source.

Legionnaires’ disease is a severe pneumonia, which is caught by breathing in tiny droplets of water containing Legionella bacteria.

These usually come from sources such as air conditioning systems, showers and taps which are not properly designed, installed or maintained.

To become infected with the disease, Legionella bacteria in the air have to be inhaled as tiny water droplets from a contaminated source.

The wider risk to public health is low as the disease is not usually passed from person to person, however.