Originally Posted by
SOLTATIO
The example I have encountered was a South African obtaining Canadian citizenship later in his life and then trying to visit South Africa on his Canadian passport. He was refused entry as he held South African citizenship and needed to present his South African passport.
Cannot vouch for Canada or other countries, but I'd advise the OP to check with the local embassy.
This would not happen in Canada. At a port en entry once I establish that a person seeking entry is in fact a Canadian citizen I cannot refuse said entry.