Former President Leonid Kuchma (search) was questioned Thursday in connection with the 2000 killing of an investigative journalist who wrote about top-level government corruption, prosecutors said.

Kuchma was questioned as a witness as part of an investigation into the slaying of journalist Heorhiy Gongadze (search), said prosecutor general's office spokesman Vyacheslav Astapov.

Gongadze's decapitated body was found in a forest outside Kiev more than a month after his abduction.

Astapov wouldn't give any details of the questioning or say how long it lasted. He refused to say whether Kuchma would be summoned again.

Kuchma's opponents have accused him of involvement in the killing. Gongadze's slaying and the release of secret recordings that allegedly implicate Kuchma sparked massive street protests and became a rallying cry that helped unite the opposition and propel it to power last fall in this former Soviet republic.

Kuchma has denied all allegations against him and has questioned the authenticity of the secret tapes allegedly recorded by his former bodyguard Mykola Melnichenko.

Kuchma's spokeswoman, Olena Hromnitska, said he had voluntarily visited the prosecutor general's office for questioning, but wouldn't give further details. "Kuchma has said that his conscience is clean before God, people and before Gongadze," she said in a telephone interview.

President Viktor Yushchenko, whose December election victory ushered the opposition into power, has said that solving Gongadze's slaying was a matter of honor for him and his administration.

Asked whether the case could reach as high up as Kuchma, Yushchenko said during a visit to Berlin on Wednesday that "everyone is equal before the law in Ukraine," his press office said.

The Gongadze case, which long sat dormant under the Kuchma administration, has proceeded rapidly since Yushchenko came into office. Prosecutors have charged two former police officials with murder in connection with Gongadze's death. Both were detained earlier this month and charges were filed Monday.

Another police official suspected of involvement remains under orders not to leave Kiev, and a fourth, senior police official Oleksiy Pukach, is being sought on an international warrant.

On Friday, former Interior Minister Yuriy Kravchenko was found shot to death in an apparent suicide hours before he was due for questioning in the case.