Conservative Russian lawmaker and Putin ally Vitaly Milonov is in hot legal pursuit of Lady Gaga on the gay rights issue as the singer tours Russia, according to Reuters.

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Milonov is known for his legislation banning "homosexual propaganda" in St. Petersburg, where Lady Gaga appeared in a Sunday concert. He accused the US singer of trying to get 12-year-olds to support the LGBT (lesbian, gay, bisexual and transgender) cause, said The Guardian. Milonov will file a lodge a formal complaint with St. Petersburg prosecution, reported Reuters.

The move could cost Lady Gaga. Madonna got in a similar mess during her tour of Russia, according to Britain's The Times, and it ended up costing her $10.7 million in legal fees. She was put on trial in absentia just last month, reported The Guardian.

Milonov seems similarly dogged in his pursuit of Lady Gaga. "We will contact prosecutors and the law enforcement agencies to carry out a thorough investigation of the situation," The Guardian cited Milonov as telling the pro-Kremlin Life News tabloid.

"When people tell kids 'you must support sexual minorities', that can create a false equivalence for them between traditional and non-traditional relationships," he reportedly added.

Milonov even tried, but failed, to implement an under-18 ban ahead of her St. Petersburg appearance, said Reuters.

Lady Gaga, a longtime vocal advocate of gay rights, said offstage in St. Petersburg that she'd been threatened with arrest or heavy fees if she touched the issue, Reuters cited local media as saying.

Russian lawmakers next month are set to review legislation forbidding gay rights material from appearing in public in Moscow, said Reuters.