Russia's State Duma has approved legislation aimed at preventing migrants from obtaining Russian citizenship through sham marriages, including marriages to elderly women, State Duma Speaker Vyacheslav Volodin said.

According to Volodin, the new law is intended to eliminate legal loopholes that allowed foreigners to secure citizenship through fictitious marriages, The Caspian Post reports.

"We needed to restore order... to get rid of these previously numerous grounds for sham marriages. This involved immigrants marrying women aged eighty and older. All these loopholes have now been eradicated," the speaker of the lower house said.

The amendments were adopted in the second and third readings as part of a government bill that further tightens Russia's immigration legislation.

Besides addressing sham marriages, the law introduces additional grounds for refusing Russian citizenship, temporary residence permits and permanent residence permits. Under the new rules, foreigners with any unexpunged or unspent criminal record will be denied these statuses. Previously, the restriction applied only to intentional crimes in the case of citizenship applications and to serious or especially serious crimes for temporary residence permits and permanent residence permits.

If a foreign national has already received the relevant documents and is later found to have an unspent criminal record, those documents will be revoked. The only exceptions apply to officially recognized refugees and individuals granted political asylum.

The legislation also introduces stricter documentation requirements. Migrants applying for legal status will have to submit a paper certificate confirming the presence or absence of a criminal record from their country of residence. The certificate must have been issued no more than three months before the application is filed. Applicants with multiple citizenships or residence permits will be required to provide a separate certificate for each country.

The requirement will not apply to children under the age of 14, recognized refugees, individuals granted political asylum, or foreign nationals serving under contract in the Russian Armed Forces.

The new regulations will take effect 180 days after the law is signed by the president. Applications submitted before the new rules come into force will be considered under the current legislation.

The law was adopted as part of Russia's broader effort to tighten immigration policy following the terrorist attack at Crocus City Hall.