President Viktor Yushchenko (search) said Tuesday that authorities have detained suspects in the killing of a prominent investigative journalist whose decapitated body was later found in a forest — a 4-year-old crime that the newly elected leader had promised to solve.

Heorhiy Gongadze, an Internet journalist who wrote about top-level corruption under Yushchenko's predecessor, Leonid Kuchma (search), was abducted in downtown Kiev in September 2000, and his headless body was later found buried outside the capital.

His death touched off months of protests against Kuchma, who the opposition alleged was involved in the killing. Kuchma denies the allegations.

"Gongadze's killers were detained and they are giving information to investigators," Yushchenko told reporters.

"The main task now is to get to the most important thing: who organized and ordered the murder," said Yushchenko, who did not identify the suspects.

Kiev television station TV5 reported Tuesday that Gongadze's head had been found in a lake near the Dnipro River (search)just outside Kiev, the capital. Ukraine's security agency later denied the report.

Yushchenko, the opposition leader who was elected president in December after a divisive campaign against Kuchma's chosen successor, accused the previous administration of "sheltering Gongadze's killers."

"They never wanted to pursue the case," he said.

Yushchenko has repeatedly said solving Gongadze's slaying was a matter of honor for him.

"Now I can tell my kids who killed Ghia (Heorhiy) Gongadze and how," he said.

Yushchenko pledged that the authorities will resolve the deaths of more than two dozen prominent Ukrainian politicians, businessmen and journalists who were killed or died under suspicious circumstances in the last decade.

The pro-Western leader also announced the creation of the National Bureau for Investigation, which will be tasked with pursuing other unsolved high-profile deaths and fighting corruption. "We must demonstrate that there is law in this country."

During the presidential campaign last fall, Yushchenko was hospitalized because of an illness diagnosed as dioxin poisoning. Yushchenko described it as an assassination attempt and said he was probably poisoned at a dinner with the top state security officials.

On Sunday, Ukrainian police said investigators had identified people who abducted Gongadze.

Ihor Honcharov, a former police officer and a key witness in the case, died in prison two years ago under suspicious circumstances.

Last year, a parliamentary committee recommended criminal proceedings against Kuchma as the likely suspect in masterminding Gongadze's death.