"We have a lot of things to check yet. I cannot say for certain when the former president will be summoned, although it would likely be in early March, after the Olympics," a source was quoted as saying by the news agency.
The prosecutors are currently investigating whether Lee's office received over 400 million won ($375,880) in bribes from National Intelligence Service (NIS) and whether the former president is the real owner of the DAS automotive seats manufacturer registered under Lee's brother's name and allegedly used to manage a huge slush fund for Lee.
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Lee served as president between 2008 and 2013, he was succeeded by Park Geun-hye, who was impeached in December 2016 as a result of a bribery scandal also involving NIS. The political crisis triggered investigations, which revealed various bribery cases involving top officials of the country.