The European Commission says prosecutors applying for the post of European chief prosecutor must be treated fairly, after Romania moved to block one of its own nationals.

Commission spokesman Margaritis Schinas Thursday said Brussels is following the case closely adding it is crucial that candidates put forward by an independent selection panel are "treated fairly."

He spoke after Romania's Justice Minister Tudorel Toader wrote to EU justice ministers accusing Laura Codruta Kovesi, the former chief anti-corruption prosecutor, of signing "secret and anti-democratic pacts" with the intelligence agency in corruption and national security probes. Kovesi has been shortlisted to lead the European Public Prosecutor's Office, due to become operational at the end of 2020.

Toader removed Kovesi from her post last year, citing mismanagement.

On Wednesday, Kovesi said prosecutors are probing her for official misconduct and bribery. She denies wrongdoing.