(Adds details on case, background, comment from lawyer)
By Alastair Sharp
TORONTO, June 9 (Reuters) - A Canadian judge denied a bail appeal on Friday for a man who U.S. prosecutors want to extradite to face charges he worked with Russian agents in a high-profile breach of Yahoo Inc email accounts.
Attorneys for Karim Baratov, a Canadian citizen born in Kazakhstan, had said at a bail hearing on Monday that evidence submitted by prosecutors suggested he played only a minor role in any plot but Justice J.A. Miller rejected that argument.
"At the end of the day, Mr. Baratov remains a significant flight risk and is alleged to have committed a serious offence," the ruling from Justice J.A. Miller released on Friday said. "The application is dismissed."
Baratov was arrested in March on U.S. charges that he was paid to break into at least 80 email accounts by Russian intelligence agents who masterminded the 2014 theft of data from some 500 million Yahoo Inc user accounts.
At the bail appeal hearing early this week, arguments focused on whether Baratov was merely a small-time hacker-for-hire or a key player in the scheme, the first time the U.S. government had criminally charged Russian spies for cyber offenses.
Baratov's lawyers said the indictment only presented evidence of Baratov receiving $104.20 into his PayPal account from a Russian intelligence agent for breaking into seven email accounts.
"Whether the applicant was paid nothing or was paid millions ... the alleged conduct remains a destabilizing attack on the integrity of systems that are vital to all of our wellbeing," Miller wrote.
At the time of his arrest, Baratov's social media accounts presented the image of a wealthy young man wealth who loved expensive cars.
Baratov and his family were disappointed with the decision but focusing on fighting the extradition process and defending against the allegations, his lawyer said. (Reporting by Alastair Sharp in Toronto; Editing by Jim Finkle and Bill Trott)