MONTREAL - Retired brigadier-general Daniel Menard was demoted and fined after he admitted Thursday to having had a sexual affair with a subordinate in Afghanistan and then lying about it.

A court martial judge, Lt.-Col. Louis-Vincent d'Auteuil, downgraded Menard, 45, to colonel and fined him $7,000 after he pleaded guilty to two counts of conduct to the prejudice of good order and discipline contrary to the National Defence Act.

Menard will have a criminal record as a result of the ruling, a major fall from grace for a man who 18 months ago was one of the brightest stars in the military after he was promoted to general at just 43 years of age.

"(The affair) was in the worst place at the worst time," the judge said to Menard as dozens of soldiers and journalists looked on.

"You were in the theatre of operations ... it was a violation of the trust placed in you by your superiors and your subordinates."

Menard had sexual relations with Master Cpl. Bianka Langlois while he served in Kandahar as Canadian Forces Task Force commander. He then lied about the affair and pressured her to do the same.

Menard, a married father of two, agreed to the statement of facts that outlined his tryst with Langlois between November 2009 and April 2010.

He kissed the corporal at least twice in his office at Kandahar Airfield and had intercourse with her in his quarters - a direct violation of fraternization rules that he had agreed to and was tasked with enforcing.

The affair first came to light when someone sent an anonymous e-mail about the fling to an American blogger not long after the affair ended in April 2010. A Canadian Forces public affairs officer became aware of the e-mail and informed Afghan commanders serving under Menard.

When confronted about the allegations, Menard twice denied the affair, saying only that he and Langlois enjoyed a "great friendship." Langlois, meanwhile, had admitted to the tryst under interrogation.

On May 28, 2010, Menard confronted his ex-lover and asked her change her story and delete all e-mails that pointed to the affair.

Court documents state Menard pressured the corporal by asking her to consider "what effect the revelation would have on her career, the mission (and) the Canadian Forces in general."

Langlois agreed to the coverup, but Menard had a change of heart the following day and admitted to the relationship.

He was quickly relieved of his Afghan command and sent back to Canada. His career in ruins, he retired late last year.

Menard took the stand Thursday, expressing no remorse over his actions but instead recounting the effect the affair has had on his career.

"(It was) by far the worst (thing) I had experienced in my life, including all of the (military) conflicts I've been involved in," said Menard, whose wife is also a soldier.

"The last few months were extremely difficult. I was afraid I would lose my family."

His lawyer, Jean Asselin, said the media coverage has been excessive and that Menard's transgressions pale in comparison to those of former colonel Russell Williams, who is serving a life sentence for raping and murdering two women.

The military's lawyer, Cmdr. Martin Pelletier, told reporters Menard's attitude was disappointing.

"The defendant talked about himself during his testimony," Pelletier said.

"I was a bit surprised that he didn't say sorry to his troops. I think that's unfortunate ... he was their commander."

Pelletier added that Menard only has himself to blame for his fall.

"What happened to general Menard's career is unfortunate, but we have to remember that it's the result of choices that he made."

Langlois was convicted in a summary trial in September and was reprimanded and fined $700.