The tortoises, worth pounds 300 each, are part of a group of seven stolen a fortnight ago. Two are still missing.
They were being cared for by Carol Kemp, who breeds reptiles in the back garden of her home. The location is being kept secret to protect her animals from further raids.
Rosemary Suswillo, of the Royal Veterinary College, said the black market in such animals had risen since an import ban was introduced 10 years ago.
Mrs Kemp said: 'Tortoises used to cost only a couple of pounds, but now it is almost impossible to buy them.
The pet shop was raided by police after Mrs Kemp visited it and identified her missing animals.
A man has been cautioned by police under the 1985 Endangered Species Act.Reuse content