He should probably start his investigation in the jurisdiction where he received the DUI conviction. Canada has some pretty harsh conditions regarding entry into their country where DUI charges are at issue. An immigration attorney can help with the paperwork that is necessary to get "rehabilitated" for the purpose of this immigration.
Best of luck.
How and where did you find out that he has no criminal record? It is possible that Canada is using a different criminal background check source (e.g., federal vs state or local records). I suggest you continue with your application and if you have already done so, contact the Canadian Embassy and Consulate in Minneapolis at 612-333-4641. Gaining access into Canada is not simple task and you should seek assistance.
Disclaimer: This communication is not intended as legal advice, and no attorney client relationship results. Please consult your own attorney for legal advice. This is for entertainment purposes only.
From the facts you stated I assume that your boyfriend was actually convicted of DUI in 1997. If that was his only conviction for anything, ever, he should be deemed automatically rehabilitated by the Canadian government because ten years have passed. He should be admissible. If there is a question about that he can apply for rehabilitation status through a Canadian immigration attorney or one of the processing services.
If he has any other conviction for anything at any time he must apply for either a temporary resident permit or rehabilitation. It sounds like he already applied for the TRP. If it was granted he should be able to enter. If this is an ongoing problem he should consult Canadian immigration counsel.
My avvo article about going to Canada with a DUI may help you understand this better. The link is below.
Wayne R. Foote, Esq.
Board Certified OUI Defense Law Specialist
by the National College for DUI Defense, Inc.
Law Offices of Wayne R. Foote, PA
344 Mt. Hope Ave
Bangor, ME 04401
(207) 990-5858 (fax)
"Injustice anywhere is a threat to justice everywhere." M. L. King, Jr.