Army deputy spokesman Col Winthai Sivari confirmed that Yingluck has been released from the army's detention.
Winthai said he could not tell what status Yingluck was in now and whether she was being monitored by army officers or not, The Nation reported.
The armed forces seized power in a coup on Thursday after months of turmoil that paralysed much of the government and caused deadly clashes in Bangkok.
The junta put Yingluck along with about 200 ousted government leaders, political figures, critics and academics in a sweeping roundup since the coup.
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Yingluck is the sister of Thaksin Shinawatra, who was ousted as premier in a military coup in 2006. Thailand has faced a power struggle since Thaksin was ousted by the military as Prime Minister in 2006.
The latest unrest began last year, when anti-government protesters embarked on a campaign to oust Yingluck's government. They accuse Yingluck of acting as a proxy for her fugitive brother.
The military moved in after months of anti-government protests, often violent, left over 28 dead and scores injured.
Suthep, who had been kept in military detention after reporting to the National Council for Peace and Order, was freed and taken to Court to face the charges.
Suthep is also facing summons on an insurrection charge for leading the anti-government protests against then prime minister Yingluck.