Sheikh Mohammed has been exonerated from any direct involvement in the Godolphin doping scandal.

The Emirati ruler and leading owner instructed the former Metropolitan Police chief commissioner Lord Stevens to review the damaging series of reports last year concerning his equestrian operations.

The British Horseracing Authority disqualified his Gogolphin trainer Mahmood Al Zarooni for eight years for injecting horses with anabolic steroids, while banned veterinary goods were seized from a Dubai Royal Air Wing flight at Stansted Airport by the UK Border Agency and the Veterinary Medicines Directorate.

Other unlicensed products were discovered at Moorley Farm in Newmarket, owned by the sheikh's Darley Stud operation.

The review made a number of key findings.

It said the seizures at Stansted and Moorley Farm resulted from "management failings, insufficient oversight, and complacency within the organisation", but confirmed the BHA findings that Mahmood Al Zarooni acted alone in procuring and transporting drugs to the UK.

It also said the seized veterinary products are widely used and considered safe and not "illegal" despite being improperly imported to the UK.

The quantity of medicines seized at Stansted and Moorley Farm were not considered unusual given the size of the operation, and were a contingency supply.

There was no link between the Al Zarooni case and the seizures.

The investigation has led to recommendations of stronger management, clearer accountability and better internal communication within the equestrian organisation, as well as the establishment of an internal compliance unit to operate independently within the operation.

"Although HH Sheikh Mohammed's equestrian operations are unusual in their size and scope, our review has highlighted the complexities of a regulatory framework that is a challenge for the entire equestrian industry," Lord Stevens said.

"Throughout our investigation of the three entirely separate incidents, we have established that no evidence whatsoever exists to suggest that HH Sheikh Mohammed had any knowledge of the purchase, transportation or use of any unregulated medicines. Equally neither did he have any knowledge of the illegal activities of Mahmood Al Zarooni.

"... in our discussions with HH Sheikh Mohammed, he agreed to create a task force of experts to suggest ways to make it easier for all affected stakeholders in the equestrian industry to comply with the regulations.

"He will ask the task force to consider the creation of a global database containing country-by-country information on registered products that could be easily accessible to those seeking to transport veterinary medicine."