Nigeria has struck off 50,000 ‘ghost workers’ from the state payrolls this year, saving nearly 630 million euros, the presidency said Tuesday.

The office of President Muhammadu Buhari, who was voted into power last year vowing to stamp out endemic graft in Africa’s most populous country, said 11 people were undergoing probes in this connection and some of them were on trial.

“The Federal government payroll has been rid of 50,000 ghost workers, saving the country a huge amount of 200 billion naira,” spokesman Garba Shehu said.

“The flagship programme of the Muhammadu Buhari administration to rid the system of fraud and instil good governance is on course,” it said.

Last week, the Nigerian government promised to protect and hand out hefty rewards to whistleblowers who could be entitled to between 2.5 and five percent of funds recovered from information they provide about corruption.

Buhari has repeatedly accused the government of ex-president Goodluck Jonathan of a “mind-boggling” looting of the treasury.