Mohammad Jahazi held a high-level post at the NRC's Institute for Aerospace Research but left Canada in 2008 after Ottawa rejected him as an immigrant for security reasons.

Federal Immigration officials told the Iranian scientist they suspected he had taken part in Iran's arms efforts and had supplied information to Tehran on Iranian dissidents in Canada and Europe.

Mr. Jahazi denied the allegations and finally Justice Yves de Montigny of the Federal Court of Canada set aside the Immigration department's ruling and sent it back for another determination.

"Our lawyers are reviewing the court's decision carefully. It goes without saying that we're disappointed by the ruling," said Alykhan Velshi, spokesman for Citizenship and Immigration Minister Jason Kenney.

"As ordered, this matter will be considered by another decision-maker in accordance with the Federal Court's decision.”

"That said, the government's position before the Federal Court was that Mr. Jahazi was inadmissible to Canada under section 34(1)(f ) of the Immigration and Refugee Protection Act as a member of an organization engaged in subversive activities and was associated with groups engaged in terrorist activities and subversion."