Former Heart of Midlothian owner Vladimir Romanov was arrested in Russia earlier this week.
Reports suggest that the Lithuanian businessman, who is wanted on embezzlement charges, was detained and then released in Moscow.
Romanov, who invested in Hearts in 2004 before the Edinburgh club went into administration last summer, was reportedly in Moscow to receive treatment for a stroke.
Lithuania president Dalia Grybauskaite believes Romanov's arrest on foreign soil is another case of Russia stepping in when they are not required.
"If this is confirmed, it's further proof that Russia is once again defying international obligations and international law," she said.
