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Misiunas did not stop to answer questions from a BNS journalist after he left the STT building in Vilnius. He told BNS that he had been questioned as a witness.
"I was asked to come to testify, but I can't give more details," he told BNS.
STT said on Thursday that it had opened a pre-trial investigation into a suspected leaking of classified information made available to the Finance Ministry about a candidate to become a member of Lietuvos Energija's supervisory board. The agency would not comment in more detail about the probe.
Finance Minister Vilius Šapoka told BNS that the STT probe did not involve the ministry's top officials, but gave no further details either. STT officials on Wednesday visited the Finance Ministry, which is Lietuvos Energija's sole shareholder, and took certain documents.