A delegation of Russian officials will visit Ankara tomorrow to investigate the murder of Russian Ambassador Andrei Karlov by a Turkish police officer linked to the Gülenist Terror Group (FETÖ), Sabah newspaper reported.

The delegation will consist of a prosecutor, a security attache and forensic experts who will meet officials from the Turkish National Police and the prosecutor's office that is conducting the investigation into 2016 killing of Karlov.The visit comes amid new arrests in the case. A police officer accused of "handling" Mevlüt Mert Altıntaş - the off-duty police officer who killed Karlov - on behalf of FETÖ was remanded in custody last week, while authorities re-arrested Timur Özkan, organizer of the exhibition Karlov was attending when he was gunned down in Ankara. Özkan was released earlier but the Sabah newspaper says new evidence showing his connection to Hayreddin Aydınbaş, another FETÖ-linked suspect tied to the murder, was revealed.

Karlov was speaking at the opening of a Russian-themed exhibition in an Ankara art gallery when he was shot dead by Altıntaş. Altıntaş was killed in a shootout with police inside the gallery. The assassination was at a time of thaw in strained Turkish and Russian relations and the investigation found that Altıntaş was linked to FETÖ, blamed for last year's coup attempt in Turkey. Since the murder, Ankara and Moscow gradually made progress in rebuilding ties that were derailed by the 2015 downing of a Russian fighter jet over the Syrian border by the Turkish military.

Investigators have learned that Altıntaş changed his cellphone number one month before the murder and borrowed a new suit from his roommate Sercan B., who is also a police officer, for "a meeting with a beloved brother," according to the roommate who was also placed under arrest for his links to Altıntaş. Prosecutors believe the person he met inside of a five-star hotel ordered the assassination.