Turkey's MIT intelligence service has been spying on hundreds of people in Germany suspected of being part of an anti-Erdogan movement, reports say.

The scale of espionage emerged after the head of MIT handed a list to German foreign intelligence chief Bruno Kahl, according to German media, according to BBC.

As well as addresses and phone numbers, the Turkish official apparently also provided surveillance photos.

The two countries are already involved in a row over a Turkish referendum.

German authorities, in common with several other EU states, barred Turkish ministers from holding rallies to campaign for increasing the powers of President Recep Tayyip Erdogan.

An estimated 1.4m Turks are eligible to take part in the 16 April referendum, and voting in Germany and five other European countries began on Monday.