Gurdev Singh Dhillon was sentenced to four years in jail in 2005 in connection with a sexual assault which allegedly took place in 2004.
A Crown review of the conviction found material evidence in the case was not disclosed.
Surrey RCMP apologized for the incident and the Crown said Dhillon could apply to have the conviction reversed.
But Paul Briggs, Dhillon's former lawyer, told CBC News the apology and admission come too late, as Dhillon was deported in 2008 because of his sex assault conviction.
"His entire life has been ruined," Briggs said.
Briggs represented Dhillon on a failed appeal of his conviction. Dhillon claimed he wasn't one of two men accused of raping a young woman.
Briggs has since learned there was DNA evidence in existence that would have helped Dhillon's case.
"That there would be evidence that would assist my client that was not made available to me — it's very shocking," he said.
"There's no question this ought to have been disclosed. The question is why it wasn't.
"There is going to be some potentially serious repercussion here," Briggs said.
Two other men, Mohammaed Zaaid Ukhttar and Sital Singh Bhati, have now been charged in connection with the alleged sexual assault.
Briggs said the criminal appeal needs to be reopened and Dhillon's conviction set aside.
Briggs said he has been trying to get in touch with his former client, who is likely now in India.
Dhillon was a permanent resident of Canada, but because he was sentenced to more than two years, he had no right to fight removal from the country.