Ukrainian citizens Hennadiy Afanasyev and Yuriy Soloshenko, who were convicted in Russia, are expected to be flown to Kyiv by the Ukrainian Defense Ministry's airplane in the afternoon on Tuesday, a Moscow source familiar with the situation told Interfax.

"The Ukrainian Defense Ministry's airplane, which is supposed to fly Afanasyev and Soloshenko, convicted in Russia, back home, is preparing to take off from Kyiv and head to Moscow," he said.

"The Ukrainian side has postponed its departure time several times," the source said.

The source did not say exactly when the plane would depart to Moscow.

The source said that upon their arrival to Ukraine, Afanasyev and Soloshenko will be hospitalized. He recalled that Soloshenko has cancer, while Afanasyeva has been diagnosed a blood disorder.

Meanwhile, the Ukrainian website hromadske.ua said that Afanasyev's mother Olha confirmed the possibility of the return of the two Ukrainians home on Tuesday.

Prosecutor General Yuriy Lutsenko said earlier two Russian citizens Yevgeny Mefedov and Maxim Sakauov, who are suspects in the May 2, 2014 events in Odesa, may be exchanged for Soloshenko and Afanasyev.