Scotland Yard officers carried out inquiries as part of Operation Alice, the investigation in connection with an incident involving then Cabinet minister Andrew Mitchell in Downing Street.
A copy of the file handed to the Crown Prosecution Service was also given to the Independent Police Complaints Commission, which is supervising the investigation.
The incident in September last year became popularly known as "Plebgate" following claims, denied by Mr Mitchell, that the MP called officers "plebs" in a dispute.
More top news
A senior employee at the organisation reportedly derided the three-year-old royal for being 'royal, rich' and "advantaged'.
The company plead guilty to two counts of breaching the Health and Safety at Work Act after the grisly accidents.
In the run-up to the Rio Olympic Games, ITV News speaks to four Olympic hopefuls in Team GB. Today we profile gymnast Claudia Fragapane.