Prosecutors have cited the recordings, which a former presidential bodyguard says he made in Mr. Kuchma's office from 1999 to 2000, in linking the ex-leader to the murder of the journalist, whose headless body was found buried in a forest outside Kiev in November 2000.
Mr. Kuchma, 72 years old, has long insisted the recordings were doctored.
His lawyers on Thursday prevailed in persuading a Kiev court to order an investigation into how and why the bodyguard, Mykola Melnychenko, made the tapes.
The ruling was the latest twist in a saga that has gripped Ukraine—both by dredging up explosive allegations against Mr. Kuchma and raising questions about why they are surfacing now, under the leadership of President Viktor Yanukovych, who was once a Kuchma protégé.
Prosecutors appointed by Mr. Yanukovych surprised many in Ukraine in March when they charged Mr. Kuchma with actions they say led to the murder of muckraking journalist Georgy Gongadze.
Mr. Kuchma denies the charge and currently awaits trial.
The prosecutors have said they have authenticated the portion of the tapes that pertained to the Gongadze murder.
But until recently they insisted they couldn't prove the tapes' authenticity and never used them in court.
It wasn't clear immediately after Thursday's ruling how the tapes would be authenticated.
But the conclusion could go a great distance in helping to frame the last decade in Ukrainian politics.
Some political analysts say Mr. Yanukovych is trying to display his power and independence, and say the case against the man who elevated him to prime minister in 2002 is timed to blunt Western concerns about criminal probes into other opponents, which U.S. and European Union officials say appear to be politically driven.
"It's a diversionary tactic," said opposition leader Yulia Tymoshenko, a former prime minister who is set to appear in court Friday in a separate case on charges of abuse of power.
Opponents of Mr. Yanukovych say the criminal case against Mr. Kuchma could be designed to vindicate him.
Mr. Yanukovych, in a recent interview, denied any political motivation and said the case would be decided by a court.
The tapes' release more than 10 years ago was a watershed event in Ukraine, which was shocked by audio recordings and transcripts that appear to capture the foul-mouthed president along with current and former top officials implicating themselves in crimes ranging from rigging elections to stealing state assets.
Mr. Melnychenko said he has "thousands of hours" of recordings from 1999 to 2000 that depict cronyism, corruption and impunity.
The tapes have never been fully released but Mr. Melnychenko and others familiar with extracts said voices on them include those of Mr. Yanukovych, then a regional governor, and Prime Minister Mykola Azarov, then head of the powerful state tax administration.
A spokeswoman for Mr. Yanukovych declined to comment on whether his voice was on the tapes.
Mr. Azarov said through a spokesman that the recordings weren't authentic.
Renat Kuzmin, a senior prosecutor, said other recordings hadn't yet been investigated.
The U.S. has given credence to one extract from the recordings.
In 2002, the Bush administration froze aid to Ukraine after authenticating a section in which Mr. Kuchma appears to approve the sale of a Kolchuga radar system to Saddam Hussein's Iraq.
In extracts first leaked to journalists by an opposition politician in November 2000, Mr. Kuchma allegedly discussed with top officials how to silence Mr. Gongadze, a harsh critic of his rule who founded a news website that published investigations into government corruption.
In one widely circulated audio file, a voice that Mr. Melnychenko and others familiar with the tapes allege is Mr. Kuchma's pesters then-police chief Yuri Kravchenko to get rid of Mr. Gongadze.
The voice on the file says: "Throw him out, drive him out, give him to the Chechens."
Those revelations triggered a protest movement against Mr. Kuchma that culminated in the Orange Revolution in 2004, which propelled Viktor Yushchenko into office ahead of Mr. Yanukovych, the incumbent's hand-picked successor.
Mr. Yushchenko pledged during his campaign to solve the crime, but while three police officers were convicted of the murder and sentenced to lengthy prison terms, critics continued to press for an investigation into who masterminded the killing.
The mystery around the case deepened in 2005, when Mr. Kravchenko, the police chief, was found dead from two gunshots to the head in what investigators called a suicide.
After Mr. Yanukovych won Ukraine's February 2010 presidential election, prosecutors said Mr. Kravchenko ordered the murder, a move critics called a coverup.
Source: The Wall Street Journal