Lady Gaga has been accused of promoting gay rights to minors during a concert on Sunday in St. Petersburg, Russia.

A law which criminalizes “public actions aimed at propaganda of pederasty, lesbianism, bisexuality and transgenderism among minors” took effect in St. Petersburg earlier this year.

The measure's architect, Vitaly Milonov, accused Lady Gaga of violating the law.

“We saw that in addition to music, songs and such, there were direct calls for 12-year-old citizens to support the LGBT [lesbian, gay, bisexual and transgender] community,” Milonov is quoted as saying by Reuters.

“We will contact prosecutors and the law enforcement agencies to carry out a thorough investigation of the situation,” he told Russian tabloid Life News. “When people tell kids 'you must support sexual minorities,' that can create a false equivalence for them between traditional and non-traditional relationships.”

Earlier, Milonov had attempted to bar anyone under 18 from attending Lady Gaga's show.

The Guardian reported that Lady Gaga called for respect of gay rights.

“Lady Gaga wants to say that she expects respect from others – she's not here to offend anyone's religion or faith, she's here to unite us,” she said speaking through a translator.

Local media reported Lady Gaga saying that her managers had been threatened with fines or arrest if she spoke in support of gay rights.

On Saturday, the singer tweeted thanks to Russian Prime Minister Dmitry Medvedev for what she perceived as opposition to a proposed federal ban.

“Thank you Prime Minister Medvedev for not standing by your party's anti gay propaganda law & instead supporting my show+fans all over Russia,” she messaged to her nearly 32 million Twitter followers.

Medvedev commented on the proposed legislation during a live television interview on Friday.

“Not all moral issues, not all behavioral patterns, not all issues of communication between people need to be regulated by law,” Russian media reported Medvedev as saying.

Lady Gaga has strongly voiced her support for gay rights in the United States.

(Related: Madonna cleared of claims she violated Russian city's anti-gay law.)