Lord Stevens will conduct an internal inquiry into the global racing empire of Sheikh Mohammed.
The former Metropolitan Police chief, 70, has already begun the process of "assembling a team of experts" for an investigation which is likely to continue into the new year.
Sheikh Mohammed's racing organisations were placed under the spotlight after former Godolphin trainer Mahmood Al Zarooni was found to have given banned anabolic steroids to 22 of his horses in April.
A consignment of veterinary products from Moorley Farm, which is owned by Sheikh Mohammed's Darley Stud Management Co Ltd and is used for training endurance horses, was seized in Newmarket in August.
Last month the British Horseracing Authority said it had been assured the seized products were not related to racing, a stance it reiterated on Monday, and were a matter for the VMD and Defra (Department for Environment, Food and Rural Affairs).
Lord Stevens was asked to spearhead the inquiry following a meeting with Princess Haya, Sheikh Mohammed's wife, on Tuesday.
He said in a statement: "I have been asked by His Highness Sheikh Mohammed to oversee an internal inquiry that will examine organisational structures, internal communication and veterinary practices at all of the major components of Sheikh Mohammed's equestrian properties and operations, including Darley, Godolphin, Meydan and Janah, the equine flight company.
"We will look into events surrounding the seizures at Stansted and Moorley Farm, including the chain of custody for the medications in question and their intended purpose," said Lord Stevens, who over a decade ago presided over an external police inquiry in Northern Ireland into allegations of collusion between the RUC, the army and loyalist terrorists.
"We will also look beyond those specific events for a wide-ranging assessment of veterinary procedures and practices to determine whether they are in support of horse welfare and in keeping with all applicable laws and regulations.
"Sheikh Mohammed is adamant that any evidence of violations of law or regulation in any jurisdiction should be shared with the appropriate authorities.
"Our primary focus is on preventing any future systemic failures.
"We will identify best practices and develop protocols and procedures to streamline and improve management and operations.
"Following my meeting with Princess Haya on Tuesday, I have begun assembling a team of experts for this task.
"At this earlier stage, it is difficult to predict when we will complete this project, but our work will undoubtedly extend into the new year.
"We have agreed that we will not wait until the inquiry is finished to suggest any improvements that should be implemented more quickly."
Meanwhile, trainer Charlie Hills has another nice horse with which to go to war next season after Cambridge created a sound impression on her debut at Nottingham.
The Rail Link filly needed every yard of the extended one mile on her debut and ran out a cosy winner, beating Regardez by three-quarters of a length in the Sir Henry Cecil Oh So Sharp EBF Maiden Fillies Stakes.
"She was extremely impressive and I believe she will be better over further distances next season," said jockey Ted Durcan.