KIEV, September 23 (RAPSI) - Former Ukrainian Prime Minister Yulia Tymoshenko on Monday refused to attend a hearing in the criminal case over fraud at the United Energy Systems of Ukraine (UESU), RIA Novosti reports.

The case has been postponed for over a year, due to the ex-prime minister's poor health, which has required her to undergo treatment at a Kharkov hospital.

In October 2011, Tymoshenko was sentenced to seven years in prison for abuse of power. The judge said she abused her powers when she signed a 2009 deal with Moscow under which Ukraine paid a high price for Russian gas.

She also faces accusations in a high-profile murder case.

Evhen Shcherban, head of the Aton financial corporation and a deputy of the Supreme Rada, was shot dead at Donetsk Airport in November 1996. His wife and an airport employee were also killed.

The Prosecutor General's Office claimed that the murder was ordered by two former Ukrainian prime ministers, Tymoshenko and Pavlo Lazarenko.

According to the investigators, Shcherban stood in the way of making United Energy Systems of Ukraine, which Tymoshenko headed at the time, the monopoly distributor of gas in the Donetsk Region. The investigators claimed that Tymoshenko and Lazarenko paid $2.8 million for Shcherban's murder. If Tymoshenko is found guilty as charged she could be sentenced to life in prison.