Asked by the press why he changed his mind, Hedl, who works for the Split-based weekly "Feral Tribune", said that he did so because of his "enormous respect for the judge and the court" in charge of the case.
"Take it as you want," the reporter added.
Hedl, who has been writing for years about the killings and abductions of Serb civilians in Osijek in the early 1990s and Glavas's role in those events, would not reveal the content of his testimony which lasted more than two hours, because the proceedings are confidential.
In mid-August Hedl issued a statement for the press saying that he would not respond to the court summons to testify in the case even under the threat of arrest.
"My decision not to testify is not due to fear of Glavas and his storm troopers, but due to my protest against the fact that such things are not being punished and that what Glavas is saying and doing is being tolerated," Hedl said at the time.
The Zagreb County Court has been investigating Glavas since June this year. Glavas is suspected of having personally ordered the murder of two Serb civilians and the ill-treatment of another three in Osijek in 1991.
The investigation will continue on Wednesday with new witness testimonies.
Glavas was stripped of immunity on Monday due to his suspected involvement in the abduction and execution of Serb civilians on the Drava River banks in late 1991. The Osijek County Court has launched an investigation into six members of the Independent Uskok Unit for that crime.
Osijek County Court investigating judge Mario Kovac last night did not decide about the prosecution's request that this investigation also include Glavas, saying that the investigation was not within the jurisdiction of the Osijek County Court.
The judge explained that criminal proceedings against Glavas for the same type of crime - war crimes against civilians - were already being conducted by the Zagreb County Court.
Dismissing media reports that the Chief Public Prosecutor had considered resigning after this decision, the spokeswoman for the Chief Public Prosecutor's Office, Martina Mihordin, said that the Osijek County Prosecutor's Office would appeal against Judge Kovac's decision, as well as against his refusal to put Glavas in custody until a decision was made on which court should be in charge of the investigation. Mihordin said the Osijek County Court would decide on the two appeals.
Officials at the Chief Public Prosecutor's Office would not comment on yesterday's decision by the Parliament's Credentials and Privileges Commission to postpone a discussion on the Zagreb County Court's request to strip Glavas of immunity, saying that the request was legally questionable because the investigating judge had ruled detention before Glavas was stripped of immunity.