The Boryspil prosecutor's office served Radical Party leader Oleh Lyashko with a notice of suspicion over his fight with MP Andriy Herus.
Prosecutors intend to ask the court to place Lyashko into custody.
"Not Herus who betrayed Ukraine and let Russian electricity flow in here, but Lyashko who has been fighting Russian aggression should be locked. This is what the prosecutor's office asks for. All those who work against Russian aggression must be jailed. This is their policy. Volunteer fighters, politicians, army support volunteers, servicemen – all those who fight against Russian aggression must be jailed. These are the orders which the prosecutor's office carries out," Lyashko was seen saying in the video filmed by his party colleague Dmytro Linko.
Lyashko and Herus had a fight in Boryspil airport on 6 November over an amendment which allows the import of electricity from Russia.
The first import of Russian electricity was carried out on 1 October by the United Energy company believed to be associated with Ihor Kolomoyskyy.
A petition to ban Russian energy imports was registered on the president's website on 4 October.