A Russian court on Wednesday found an elderly rights activist guilty on a fraud charge she said was aimed at her work investigating Russian troop deaths in Ukraine, but then immediately amnestied her.

Lyudmila Bogatenkova, who heads a committee of soldiers' mothers in the southern Russian region of Stavropol, was given a one-year suspended sentence but had the punishment dropped straight away by the court in the town of Budyonnovsk.

"Charges were laid against me after I published a list of the Russian soldiers who had been killed in eastern Ukraine," Bogatenkova, 74, who was charged with fraud in October, told AFP.

"I spent two days with the Federal Security Service (FSB) and prosecutors. They [authorities] pressured people in my surroundings to give incriminating evidence against me. But they couldn't find anything in my finances and I have now been fully rehabilitated."

Lawyer Andrei Sabinin told AFP that prosecutors were unable to prove his client had promised a man 800,000 rubles ($14,400) in exchange for having his son released from police custody.

Bogatenkova was also cleared of additional fraud charges that had been laid against her, Sabinin said.

Moscow has repeatedly denied Ukrainian and Western claims that it has deployed troops in east Ukraine to bolster a separatist insurgency.

Rights activists and investigative journalists insist they have uncovered a growing body of evidence -- including unexplained military funerals and testimonies from relatives -- pointing to Russia's military role in the Ukraine conflict.

Russian President Vladimir Putin in May signed a decree classifying the deaths of Russian troops in peacetime "special operations" as a state secret.