Ukraine has opened a criminal investigation into former President Leonid Kuchma over the notorious murder of journalist Georgiy Gongadze in 2000.
Prosecutors said Mr Kuchma was suspected of abuse of power and giving illegal orders to the interior ministry which led to the killing.
Mr Gongadze - a critic of Mr Kuchma - was abducted in September 2000 and his headless body was found months later in a forest near the capital Kiev.
Mr Kuchma denies any involvement.
The Gongadze affair sparked massive street protests against Mr Kuchma's government.
On Tuesday, Deputy Prosecutor General Renat Kuzmin told reporters in Kiev that "a criminal case has been opened against Leonid Kuchma".
Mr Kuzmin said Mr Kuchma, who served as president in 1994-2005, "is now suspected of abuse of power and giving illegal orders to senior officials of the interior ministry that led to the murder of of the reporter".
The prosecutor also said the former president was now banned from leaving the country.
Mr Gongadze - who was the founder of the Ukrainska Pravda (Ukrainian Truth) website - had exposed high-level corruption and was an outspoken critic of Mr Kuchma.
Mr Kuchma has not publicly spoken about the decision to open the case against him.
In the early 2000s, the anti-Kuchma opposition claimed it had the proof that the former leader was involved in Mr Gongadze's murder, pointing to audio tapes secretly recorded in Mr Kuchma's office by one of his bodyguards.
The tapes contain a voice resembling that of Mr Kuchma and suggesting that Gongadze should be "kidnapped by Chechens".
Mr Kuchma has not denied the voice in the recordings was his but insists it has been doctored to make him appear to say things he had not actually said.
Although the authenticity of the tapes - which caused a sensation in Ukraine at the time - has been repeatedly questioned, Mr Kuzmin on Tuesday said that they would be recognised as valid evidence in the case.
In 2009, Ukrainian officials arrested former interior ministry official Olexiy Pukach, who later confessed to personally strangling Mr Gongadze and then beheading him with an axe. Three other officials are serving jail terms for their part in the killing.
Prosecutors earlier said that former Interior Minister Yuri Kravchenko, now dead, ordered Mr Gongadze's killing.
Mr Kravchenko is said to have committed suicide in 2005 - his body was found with two gunshot wounds to the head.