Turkey's president has defended the controversial construction of a grandiose new presidential palace, saying his old office was infested with cockroaches.

Recep Tayyip Erdogan has been accused of squandering state resources when he was prime minister by building the 1,150-room palace, which critics say was illegally built on protected land. In the run-up to Sunday's parliamentary elections, opposition parties have criticized the expenditure.

Erdogan moved into the vast structure after he was elected president in August. The former presidential palace was given to the prime minister.

In a television interview late Friday, Erdogan said cockroaches had roamed the lavatories in the now-vacated prime ministry.

He said: "Does such an office suit the prime minister of the Republic of Turkey? There can be no question of waste where representation is concerned."