Updated

An anti-corruption agency established in Ukraine two years ago was expected to be a driving force behind combatting the endemic graft that has depleted the nation's resources and worried its Western allies.

But the National Anti-Corruption Bureau of Ukraine instead has come under fire from allies of President Petro Poroshenko who are trying to curtail its operations and authority.

NABU chief Artem Sytnik told The Associated Press in an interview that fear of his agency's work is behind the attempts to weaken it.

Sytnik said: "The old and new elites are quite scared" after realizing "there are no untouchables anymore."

Poroshenko's failure to uproot corruption has caused growing public outrage in Ukraine and triggered calls for his impeachment led by Mikheil Saakashvili, the former Georgia president turned opposition leader.