The Oxford coronavirus vaccine trials are back on after being suspended for an urgent investigation because a volunteer reportedly suffered potentially dangerous side effects.

The Medicines Health Regulatory Authority (MHRA) has said it is now safe to continue the trial.

In a statement, Oxford University said: "The ongoing randomised controlled clinical trials of the Oxford coronavirus vaccine CHAdOx1 nCoV-19 will resume across all UK clinical trial sites.

"Globally some 18,000 individuals have received study vaccines as part of the trial. In large trials such as this, it is expected that some participants will become unwell and every case must be carefully evaluated to ensure careful assessment of safety.

"On Sunday, our standard review process triggered a study pause to vaccination across all of our global trials to allow the review of safety data by an independent safety review committee, and the national regulators. All routine follow-up appointments continued as normal during this period.

"The independent review process has concluded and following the recommendations of both the independent safety review committee and the UK regulator, the MHRA, the trials will recommence in the UK."

The Briton who suffered the potentially dangerous side effects is expected to recover, but Oxford University says it "cannot disclose medical information about the illness for reasons of participant confidentiality".

(With input from agencies)