I lent my brother $36,000 in 2001 while he lived in New Brunswick, I live in Ontario, my brother now lives in Nova Scotia. He denies owing me the money, I had a lawyer send him a letter, he said it was a gift. Can I try to retrieve these funds, I have cancelled cheques and visa statements, but not a promissory note

You will need to ask your lawyer because every situation is different. Has he stated any reason that he believed it was a gift ? What was the monies used for ?