An assistant at Regal Fern Lodge says it is working with the SPCA to monitor horses at its Kaitoke property.
The SPCA visited the stud farm on Monday and Kim Lewis says it was returning horses which had been in SPCA care for six months.
She said about six mares were taken into care in September by mutual agreement between Regal Fern Lodge and the SPCA "for their safety".
The mares and the foals they have subsequently had were returned to Regal Fern Lodge on Monday.
"We've requested that they do monthly on-site visual visits," Mrs Lewis said.