General Bilgin Balanlı, commander of Turkey's military academies, is the highest-ranking serving officer among nearly 200 serving and retired officers charged with involvement in the alleged conspiracy, dubbed "Operation Sledgehammer" (Balyoz). The case has exacerbated strains between Turkey's secularist military and a ruling party with roots in banned Islamist movements as campaigning heats up for the June 12 election.
The Istanbul court ordered General Balanlı be sent to jail pending trial on the recommendation of a prosecutor who questioned him for three hours on Monday, broadcasters reported.
Most of the defendants are held in jail near Istanbul.
The court released five other serving generals, two colonels and an admiral summoned for questioning on Friday after the seizure of documents at a retired colonel's house.
Erdoğan, whose ruling AK Party is expected to win a third successive term in office, declined to comment on the detention.
Turkish media reports have suggested that the decision to question the generals was behind the surprise last-minute can
FORMER PRESIDENT FACES QUESTIONINGcellation of major military exercises in the Aegean region last week.
Separately, prosecutors have asked two generals who led a 1980 coup to testify in an investigation on suspicion of "seeking to change the constitutional order by armed force".