"Late Thursday, Russian energy expert Evgeny Kalinin was arrested at the Athens airport. The arrest was made at the request of Ukraine. Kalinin was in Greece on a business trip. He is a well-known oil expert," Rahiotis said.
Rahiotis noted that a hearing on Kalinin's case took place on Friday and he was then sent to jail until Ukraine's extradition request would be transferred to Greece.
At the same time, Rahiotis said he was sure that it was a political case, as Kalinin was on the list of Ukraine's Mirotvorets website, which was known for publishing private information of people who allegedly posed a threat to Ukraine's sovereignty, for his support of former President Viktor Yanukovych.
The Russian Embassy in Greece told Sputnik that it provided all necessary assistance to Kalinin.
"From the very first moment we have been providing the detainee with all necessary consular assistance," the embassy said.
Kalinin was vice president of TNK-BP Commerce in Ukraine until 2011, when he resigned from the company.