A Russian court has sentenced a married couple in Kaliningrad to lengthy jail terms after finding them guilty of spying for Latvia and state treason.

The wife, Antonina Zimina, received 13 years in a penal colony while her husband, Konstantin Antonets, was sentenced to 12 1/2 years in a maximum-security prison.

The prosecutors had requested 14 years for Zimina and 13 years for Antonets.

The couple denied any wrongdoing and will appeal the verdict, their lawyer, Mikhail Bayev, said.

Antonets and Zimina were detained in July 2018 in Kaliningrad and went on trial behind closed doors in May.

They were charged with treason after state prosecutors accused them of sharing a photograph with Latvia of a counterintelligence officer from Russia’s Federal Security Service (FSB) who had attended their wedding.

The daily Kommersant reported in February that some videos and photographs from the couple’s wedding were later published on social media and were eventually included in an unspecified Baltic television program, prompting the FSB to open a criminal investigation.

In recent years, the number of cases of alleged high treason has increased dramatically in Russia.

One of the latest high-profile high treason cases involves Ivan Safronov, a journalist and an aide to the Russian Roskosmos space agency chief, Dmitry Rogozin.

Safronov was arrested on July 7 and later charged with passing classified materials to the Czech Republic.

With reporting by Reuters, Interfax, and The Moscow Times