An investigation has been launched into hundreds of paramedics over allegations of cheating in their exams.
The London Ambulance Service has called in external investigators after a whistleblower made claims about in-house exams.
Before sitting the final test, it has been claimed some students may have had access to the exam paper.
More than 800 paramedics have qualified through this exam and 650 are working for the emergency services.
But London Ambulance Service chief executive Ann Radmore told the Evening Standard it is ‘just one allegation’ that is being taken seriously.
Asked whether Londoners were at risk, Ms Radmore said: "I believe Londoners can be confident in what we are providing. They can also be confident we are taking this very seriously."
The service has 1,700 paramedics out of 3,200 clinical staff, which also includes emergency medical technicians and A&E support staff.