Officials in Kyiv say the sister of jailed pilot Nadezdha Savchenko is now back in Ukraine after she was detained on the Russian border.
Border guards reportedly stopped Vira Savchenko as she was trying to cross back into Ukraine in a diplomatic car.
She had been in Russia for a court hearing for her sister’s case.
Her passport was confiscated but has now been returned.
Nadezdha Savchenko has reportedly abandoned a hunger-strike due to reports that a prisoner-swap is being negotiated.
Ukraine has convicted two Russian soldiers of supporting separatist fighters.
What have the lawyers said?
Vira Savchenko was told she was on the Russian federal wanted list, according to her lawyer Mark Feygin.
A criminal case has been opened against her after she allegedly insulted a judge in Grozny, the capital of Chechnya, he added
Why is her sister being held?
Her sister Nadezdha was sentenced to 22 years in prison in March.
She was found guilty of involvement in the killing of two Russian journalists during separatist fighting in eastern Ukraine.
She denies the charges and says she was abducted and illegally taken to Russia to stand trial.
What has the Kremlin said?
There has been no comment so far from the Kremlin.