Head of the Joint Investigation Team and Dutch chief prosecutor Fred Westerbeke has called on Ukrainian authorities to prevent the transfer of "Donetsk People's Republic" ("DPR") fighter Volodymyr Tsemakh to Russia within the framework of a prisoner swap. Tsemakh is considered a suspect in the Dutch prosecutor's office in the case of involving the shooting down of Boeing MH17. He could have important information and give testimony.

An article published on the website of the daily national Dutch newspaper NRC Handelsblad said Westerbeke sent a letter to Ukraine's Prosecutor General's Office (PGO) last Friday.

"Westerbeke writes in the letter that 'based on recent information,' the Dutch prosecutor's office considers Tseemakh a suspect. He writes that he cannot yet share the information that underlies this status with his Ukrainian colleagues," the article says.

The Dutch chief prosecutor stresses the "paramount importance" of the fact that Tsemakh, who is in custody by a decision of a Ukrainian court, "remains available for [further] interrogation."

The article says that Russian and Ukrainian media have reported that Tsemakh has become an obstacle to the prisoner swap between Ukraine and Russia.