Ukraine's Prosecutor-General has ordered a re-investigation into the killing of a prominent independent journalist, Georgiy Gongadze, whose death sparked the country's biggest political scandal since independence.

Gongadze: Conflicting reports on his death

A headless corpse - identified as that of Mr Gongadze - was found almost two years ago in a forest near the capital Kiev.

But Prosecutor-General Svyatoslav Piskun said in a statement that further DNA tests were needed because the conclusions of German, US, Ukrainian and Russian forensic experts contradicted each other.

Mr Piskun, appointed only a month ago, also ordered further analysis of secret audio recordings alleging the involvement of Ukrainian President Leonid Kuchma in the killing.

"The Prosecutor-General has announced a full authentication in a third country, which has a high level of modern electronic technology and has not before taken part in the investigation of the tape," the statement said.

The tapes were released by a former presidential bodyguard, Mykola Melnychenko, soon after Mr Gongadze's body had been found. They allegedly revealed Mr Kuchma saying that he wanted Mr Gongadze dealt with.

Mr Kuchma has denied any involvement. However, he admitted that the tapes were genuine, but claimed they had been edited to change what he said.

Body mystery

The forensic tests in Russia and the US - that had initially confirmed that a headless body was that of Mr Gongadze - were thrown into doubt last year when analysis on different samples carried out in Germany came up negative.

President Kuchma denies any involvement

Some experts say there are grounds to suspect that the samples sent to Germany were from a second body, which had also been decapitated and had identifiable marks removed.

Despite promises by Ukrainian prosecutors and President Kuchma over the highly controversial case, the opposition has accused the authorities of trying to bury the investigation, which the Organisation for Security and Co-operation has called highly unprofessional.

The Gongadze case nearly toppled Mr Kuchma when thousands of people took to the streets last year demanding his resignationt.