The Turkish government fired 350 police officers in Ankara overnight, including heads of major departments, amid a vast corruption scandal that has ensnared key allies of Prime Minister Recep Tayyip Erdogan, local media reported.

The officers were sacked by a government decree published at midnight on Monday and included chiefs of the financial crimes, anti-smuggling and organised crime units, the private Dogan News Agency reported on Tuesday.

Hundreds of police have been dismissed or reassigned across the country since the graft investigation emerged on December 17 with the detention of businessmen close to the government and the sons of three cabinet ministers, who subsequently resigned.

Around 250 people, mostly from outside Ankara, have been appointed in place of the reassigned officers, who will take up duties in traffic police departments and district police stations, broadcaster NTV reported.

Ankara police declined comment on the reports.