Ukrainian President Viktor Yanukovych on Friday sacked a top prosecutor seen as the public face of Kiev's legal campaign against jailed opposition leader Yulia Tymoshenko, officials said.
First Deputy Prosecutor General Renat Kuzmin has been relieved of his duties amid Western calls on Ukraine to free the former prime minister ahead of Kiev's plans to sign a landmark association agreement with Brussels at a summit next month.
His dismissal comes as observers are watching for signs of the Ukrainian leadership's willingness to release Tymoshenko or send her for treatment to Europe ahead of the key summit in Vilnius.
Kuzmin has been a key figure in the prosecution of Tymoshenko and has also accused her of the murder of Ukrainian lawmaker Yevgen Shcherban in 1996.
Last year, the United States cancelled Kuzmin's five-year entry visa over his controversial investigation into Tymoshenko.
Kuzmin will now serve as the deputy chief of Ukraine's national security and defence council, Yanukovych's office said.
A spokesman for the prosecutor's office confirmed to AFP that Kuzmin had been relieved of his current duties.
Tymoshenko was sentenced in October 2011 to seven years in jail on abuse of power charges. She has denied the charges, calling them a move by her rival Yanukovych to remove her from politics.
The charges were laid against her shortly after she lost a bitter presidential election against Yanukovych in 2010.
The imprisonment of Tymoshenko, who suffers from back pain, remains a key obstacle on the country's path to the signing of a broad political and free trade deal with Brussels.
Yanukovych, who has repeatedly refused to give ground over the Tymoshenko dispute, recently signalled hopes for a breakthrough.
He said last month that authorities were working closely on the case with the European Parliament monitoring mission to Ukraine.