Canada is using DNA and commercial genealogical sites to help determine the nationality of migrants whose origin is in question.

The Canada Border Services Agency (CBSA) has confirmed the use of DNA testing "when other avenues of investigation have been exhausted".

The agency could not confirm how frequently such techniques are used.

One Canadian immigration lawyer says he is personally aware of a handful of such cases.

CBSA spokesman Jayden Robertson said the agency uses DNA testing to assist "in determining identity by providing indicators of nationality thereby enabling us to focus further lines of investigation on particular countries".

"The CBSA obtains consent from the clients before submitting their information to DNA websites," he said in a statement to the BBC.

Toronto-based immigration lawyer Subodh Bharati says he is concerned about how well the privacy of those whose DNA has been collected is being protected.

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