In the early 1960s, Turkeyreceived Belgian-made FN FAL (G1) rifles from Germany
, who had procured 100,000 from FN, but then changed to the G3 rifle after FN refused to allow Germany to produce the Belgian-made FN FAL (G1) under license.
The Germans did not issue a bayonet with the Belgian-made FN FAL (G1) , so Turkey decided to add a bayonet lug to the G1 barrel and produced this makeshift knife bayonet.
Crudely constructed of a new made pressed steel hilt mated with a recycled blade from an earlier Mauser bayonet. Several variations in blade, crosspiece, and muzzle ring have been observed. The scabbard is recycled from an earlier Mauser bayonet.
Source: FN-FAL Bayonets - Other FN-FAL Bayonets
Maybe it was captured from the Turks during the invasion of Cyprus.