Pop stars Lady Gaga and Madonna are facing punishment in Russia after authorities determined they violated their visas when they held concerts there last year.

Technically, the artists were not allowed to work in Russia on their tourist visas, but experts say it appears the visa warning is a veiled attempt punish the pop stars for their vocal support of gay rights in Russia.

The investigation into their visas came at the urging of a lawmaker who has spearheaded Russia’s anti-gay campaign.

During concerts in St. Petersburg last year, both Lady Gaga and Madonna denounced the city’s harsh anti-gay law from the stage.

“Tonight, this is my house Russia. You can be gay in my house,” Lady Gaga said during her performance in December.

A few months earlier, Madonna made similar comments during her concert.

“Gay people here and all around the world have the same rights,” she said.

Those comments have landed the pop stars in hot water in Russia. The two have been accused of spreading what the law calls “gay propaganda” under St. Petersburg’s anti-gay law.

Russia hasn’t announced any plans to prosecute the pop stars, but if convicted they could face steep fines or even be banned from entering the country.

So far there has been no response yet from either Lady Gaga or Madonna.