Asmussen and members of his staff were accused of mistreatment of horses and improper medication policies.
Louis Romanet, chairman of the International Federation of Horse Racing Authorities, said Friday his group "encourages U.S. racing regulatory authorities and law enforcement agencies to leave no stone unturned in their investigation of these matters."
Romanet also took the opportunity to repeat international calls for reform of U.S. medication policies. "IFHA fully supports its North American colleagues who seek a comprehensive national reform of medication rules, laboratory standards and penalties," Romanet said in a statement.
"The adoption of a national uniform medication program is paramount to the reform of medication rules in North America and demonstrates the value of regulatory authorities working together to harmonize racing rules."