“Allegations have been brought to the attention of the Monitoring Officer that Boris Johnson maintained a friendship with Jennifer Arcuri and as a result of that friendship allowed Ms Arcuri to participate in trade missions and receive sponsorship monies in circumstances when she and her companies could not have expected otherwise to receive those benefits,” the monitoring office of the GLA said in a statement.

Arcuri and her company have not responded to CNN’s request for comment. She told the Sunday Times, “any grants received and any trade mission I joined were purely in respect of my role as a legitimate businesswoman.”

Downing Street declined to comment to CNN on the allegations, but Johnson said in BBC interview that everything was done “entirely in the proper way.”

The Independent Office for Police Conduct is involved because Johnson was in charge of the Metropolitan Police as part of his role as mayor, said the statement.