The questioning of Petro Kyrychenko, a former adviser to former Prime Minister Pavlo Lazarenko, on the criminal case on the murder of Ukrainian MP Yevhen Scherban has been postponed again.

The secretary of the hearing announced on Friday that the questioning has been put off until 1600 on May 15.

According to an Interfax-Ukraine reporter, before the beginning of the hearing during which Kyrychenko was supposed to be questioned, the secretary read aloud the decision of the investigating judge of Kyiv's Pechersky District Court, Oksana Tsarevych.

"The court hearing has been postponed until 1600 on May 15 considering a motion of the San Francisco consul general," the secretary said.

Thus, the questioning of Kyrychenko has been postponed for the second time. During the previous hearing the questioning was put off due to a motion of former Ukrainian Prime Minister Yulia Tymoshenko.

As reported, Yevhen Scherban, a member of the Liberal Party's executive committee and a Verkhovna Rada deputy, was shot dead at the Donetsk airport on his arrival from Moscow on November 3, 1996. The gunmen fled the scene by car. Scherban, his wife and a mechanic died on the spot from gunshot wounds. The plane's flight engineer died later in the hospital. Law enforcement officers ruled out there being political motives behind the case.

In April 2003, the Court of Appeals of Luhansk region sentenced Vadym Bolotskykh to life imprisonment for Scherban's murder.

Scherban's son, Ruslan Scherban, a member of Donetsk Regional Council, said at a press conference on April 4, 2012 that he had passed to the Prosecutor General's Office documents indicating Tymoshenko's and former Ukrainian Prime Minister Pavlo Lazarenko's possible involvement in his father's murder.

Tymoshenko and Lazarenko have categorically denied being involved in the murder.

On January 18, 2013, Prosecutor General Viktor Pshonka said at a briefing that the Prosecutor General's Office had finished its investigation into the criminal case on the murder of MP Scherban and that Tymoshenko had been notified of being suspected of having organized the crime, along with Lazarenko. The article of the Criminal Code under which the notification was handed envisages life imprisonment. According to Pshonka, Tymoshenko and Lazarenko paid $2.8 million for Scherban to be killed.

In February-March 2013, three witnesses for the prosecution and one witness for the defense were interrogated in court as part of the pre-trial investigation into the Scherban murder case.

Tymoshenko did not attend either of the court hearings.

As reported, earlier two criminal cases were opened against Kyrychenko and one criminal case was opened against his wife Isabella. However, later on Kyiv's Pechersky District Court ruled to cancel the cases.

Kyrychenko was accused under a criminal case against Lazarenko. In 1995-1996 two criminal cases were opened against him under Part 5 of Article 91 of the Criminal Code (appropriation of state property in especially big amount via abuse of power by an official upon preliminary collusion with a group of people) and Part 1 of Article 206 of the Criminal Code (illegal acquisition and keeping of a gun).

Kyrychenko was the key witness for the prosecution against Lazarenko in a U.S. court. Kyrychenko was released under the Witness Security Program in the U.S., but his property in Ukraine was arrested.

In summer 2012 a separate criminal case was opened against Kyrychenko. On September 27, 2012 Pechersky District Court ruled to close the criminal case due to the expiry of the limitation of time.