if he never declared u in his immigration papers not only that he cannot sponsor u but that's misrepresentation which Canada could punish with jail and deportation too (especially if he's still PR)...i would contact a lawyer or professional consultant before starting anything
I have a similar case. I migrated to Canada under independent
professional category in year 2000. I became a Canadian citizen in year
2003. I was in a relationship in since 1990 that resulted into 2 kids.
But the I was not married to this lady and at the same time I was
responsible to financing and taken care of these kids. After I became a
Canadian I went back home to married this lady under the Civil law
marriage. The ceremony took place both the traditional marriage and
Civil law marriage was conducted.
In 2004 I filled outland application for PR and she was refused because
the VO did not believed there was a genie marriage between us. I did
not appeal. In 2005, I moved to the US to work. With my US work visa, I
was able to bring her and her dependent children to US. Due to US
economy we moved back to Canada. I was able to get Visitor visa for 3
years. In January, 2011, I applied for Inland PR . Will I be able to
sponsor her and the dependent children?