Owner Sean Buckley's horses have been banned from racing in Victoria as an investigation into his breeding operation continues.
Racing Victoria confirmed that it will not take nominations for horses in which Ultra Racing or Sean Buckley are the majority owner 'until otherwise advised'.
It comes after RV in February launched an investigation into the alleged transfer of embryos from well-performed racing mares to surrogate horses.
Ultra Thoroughbreds boss Buckley has denied any wrongdoing.
However, Buckley's legal representative Damian Sheales confirmed to Fairfax Media that Buckley will be challenging the ban in court.
The majority of Buckley's horses are trained outside of Victoria and in a statement, RV confirmed the ban, which started on March 31.
"This order was made as the stewards are, and remain, concerned that Ultra Racing and/or its managing owner, Mr Buckley, have not fully complied with a direction of the stewards to provide all relevant material to them during the course of an investigation," the statement read.
"That investigation into thoroughbred breeding remains ongoing.