
The fate of Yingluck and scores of other figures in the now-deposed government and her Puea Thai party has been a mystery since they were summoned by the army early Friday as it tightened its grip on the country.
"It is confirmed that she was detained by the military since she reported to the junta yesterday," said the source, who had served in Yingluck's government and was present when she turned herself in.
He said her whereabouts remained unknown.
An army spokesman was due to hold the junta's first press briefing since the takeover at 10:30 am (0330 GMT).
AFP