Leading microbiologist warns E. coli outbreak may worsen

Emeritus Professor of Bacteriology at the University of Aberdeen Hugh Pennington has said authorities can't be certain the E. coli outbreak has reached its peak.

He said the long incubation period could see many more cases come to light.

Across Europe the number of infections has passed 1,500 cases, 17 people have died - 16 in Germany and one in Sweden.

Three British nationals in the UK have been infected, according to the Health Protection Agency.

Professor Pennington said identifying the source of the outbreak was "crucial".