The study was published as the University of Edinburgh announced it is conducting research into the causes of the condition in a bid to find a cure.

BBC: The condition can be fatal to mother and child

Structural engineers are also visiting the garage in a bid to assess the building's condition and the petrol station is closed.

BBC: Digger used for Chigwell Shell garage cash machine raid

However, a US government official - speaking under condition of anonymity - told Reuters that an adoption bid was under way.

BBC: Madonna urged to rethink adoption

However, a US government official - speaking under condition of anonymity - told Reuters news agency that an adoption bid was under way.

BBC: Madonna 'to adopt second child'