A Venezuelan judge on Monday issued an arrest warrant for the opposition’s former presidential candidate Edmundo González as part of a criminal investigation into the results of a disputed election.

The warrant was issued at the request of authorities who accuse González, a former diplomat, of various crimes including conspiracy, falsifying documents and usurpation of powers. The warrant comes just over a month after election officials declared President Nicolás Maduro the winner of an election that his opponents say he lost.

Authorities sought the warrant after González failed to appear three times to answer questions from prosecutors in a criminal investigation stemming from the disputed election results.