A high court in Turkey has decided to acquit 63 defendants out of 64 in the country's long-running "Sledgehammer" military coup plot case.

The Anadolu 4th High Criminal Court in Istanbul made the decision on Tuesday after 236 people had already been acquitted at the end of March.

Retired Brigadier General Levent Ersöz is among the 63 suspects acquitted.

One of the suspects in Ali Göznek's file has been separated from the others' case because he had not been detained.

Earlier in the day, public prosecutor Ramazan Öksüz had demanded the acquittal of the defendants in the high-profile case.

"Sledgehammer" ("Balyoz" in Turkish) is the name of a plot allegedly thought up by a junta in the Turkish Armed Forces to overthrow the government.

The plan is said to date back to 2003, one year after the ruling Justice and Development Party (AK Party) came to power. It allegedly aimed at undermining the government to lay the groundwork for a military takeover.

In September 2012, the Turkish Supreme Court had sentenced the defendants to six to 20 years imprisonment.

However, Turkey's Constitutional Court unanimously overruled that verdict in June 2014 on the grounds that the rights of the defendants had been violated, especially from digital data collection and wiretapping.

On March 31, the Anadolu 4th High Criminal Court cancelled convictions against 236 defendants in the case.

Retired generals Çetin Doğan, Halil İbrahim Fırtına, retired admiral Özden Örnek, Turkey's Nationalist Movement Party lawmaker Engin Alan have all appeared in court.

According to the public prosecutor, sound recording documents, which were accepted as evidence for this case, were not connected to the coup plot.