WINDSOR, Ont. -- A Windsor, Ont., man has been found guilty of sexual assault and extortion after a judge determined he used the threat of deportation to pressure his wife to perform sexual acts.

Ontario Superior Court Justice Paul Howard says the man, who cannot be identified to protect his wife's identity, abused his position of power.

In a decision delivered late Friday, Howard said he believes the man committed the offences on more than one occasion over the course of the couple's nine-week marriage.

However, the judge said there was only enough evidence to convict the man on one count each of extortion and sexual assault.

He was found not guilty on five other charges -- one of assault and two each of sexual assault and extortion -- that related to specific dates in their relationship.

Court heard the couple met on an online dating site in the spring of 2015 and married within weeks.

The woman testified she had arrived in Canada from Nigeria two years earlier and sought asylum but her claim was rejected.

Both she and her husband told the court they had been looking to settle down and start a family.