Ukraine intends to fire the prosecutor who spearheaded investigations into the natural gas firm that employed former Vice President Joe Biden’s son and who compiled a dossier that accused him of corruption.

Kostiantyn Kulyk, who was a deputy to former Prosecutor General Yuriy Lutsenko, failed to show up for a mandatory legal exam last month and did not file an official justification for being absent, a source told Reuters. His dismissal is expected to take place by Dec. 31.