A marriage of two brides has been officially registered in Russia’s St. Petersburg, despite the country’s laws prohibiting same-sex marriages. The couple has managed to find a loophole in the system, puzzling authorities.

The two brides arrived at the wedding registry office on Friday both dolled up in wedding dresses and holding brides' bouquets.

Surrounded by their friends, Irina and Alyona signed papers which mark the official start of their new life as a family.

The couple shared pictures from the event on their pages at Russian social network VKontakte (In Contact).

Practically speaking, the wedding is illegal and completely contradicts Russian legislation, which prohibits same-sex marriages. However, in legal terms it does not.

The trick here is that one of the brides is legally not a woman.

“Yes, in my passport it says ‘male’,” Irina has told RT.

Irina speaks of herself as a transsexual rather than transgender.

“Transgender is a term to describe discrepancies between social and biological sex. I am transsexual, meaning that despite the fact that I have XY chromosomes, psychologically I am a woman,” she explained.

Irina wears women's clothes and puts on make-up. Still on hormone therapy, visually she already looks like a real woman, though under the law she is not.

The couple has used this fact to officially register their relationship, because under the Family Code of Russia marriage is “a voluntary consent of a man and a woman.”

Thus, since Irina’s passport belongs to ‘male’ and Alyona’s to ‘female’ their marriage does not violate any law.

However, the event has begun to evolve into a scandal with St. Petersburg MP Vitaly Milonov, known for his anti-LGBT drive, vowing to launch a probe to check the legality of the marriage.

“I understood their [registry office workers'] unconvincing arguments; they formally approached the issue and saw passports, but not people. I told the head [of the wedding registry office] that it is criminal negligence,” he told NTV.

Milonov said he plans to get prosecutors involved to try to avoid such “ugly insults to millions of Russian families in the future.”

Milonov has gained popularity (or, in some people’s view, notoriety) in Russia and abroad for sponsoring the original “gay propaganda ban” – the St. Petersburg city law that introduced administrative fines for promoting non-traditional sex relations and values to minors. The bill was later passed at a Federal level, despite protests from Russian LGBT activists and international rights organizations.

Despite the threats to cancel their union, the newlyweds consider themselves the first married LGBT couple.

“This is a big step for all of us. Most of us want formally get married, but in Russia it is still impossible. For us it is the realization of our dreams. We hope many will have this opportunity,” bridesmaid Marina Teodori told the media.

However, some LGBT activists do not agree that Irina and Alyona should be considered a gay couple.

“This is in no way a same-sex marriage. This is a question of transgender, not homosexuality,” prominent gay rights activist Nikolay Alekseev told the Russian News Service. “This is an old story. There have been such cases before. A certain gender is written in a passport, but how they dress for the wedding is their business.”