Image copyright Science Photo Library Image caption A file image of medicinal leeches. Those found were Hirudo verbana

A man has been fined C$15,000 ($11,000; £8,800) for trying to smuggle thousands of leeches in his carry-on luggage on a flight from Russia to Canada.

Ippolit Bodounov was detained at Toronto's Pearson International Airport last October.

Some 4,788 wild, live leeches were found in a large reusable grocery bag, Canadian environment officials said.

The leeches, intended for medicinal usage, are regulated to control the wildlife trade.

The discovery was made after a dog working with border agents smelled the leeches.

They were then sent off for tests to determine if they were lawful, Environment and Climate Change Canada (ECCC) said in a statement.

The leeches were identified as Hirudo verbana, one of only two species of medicinal leech that come under regulations aimed at controlling wildlife trade.

"These species are regulated because over-harvesting of medicinal leeches from the wild is a major threat to the species," the statement said.

All of the leeches tested had come from the wild.

Sebastian Kvist, of the Royal Ontario Museum in Toronto, told CBC News that, surprisingly, all of the leeches survived.

Mr Bodounov - thought to be the first person in Canada to be caught importing the species - was charged with the unlawful import of a regulated species.

The parasites, which drink the blood of animals and humans, were one of the first species subject to conservation measures, including exportation restrictions, dating back to 1823.

Medicinal leech saliva contains blood-thinning properties and was vital in the first positive results of human dialysis treatments.