Garlick resigned on July 20, the president of Bosnia's State Court, Meddzida Kreso, told Dnevni Avaz daily, saying the reasons for the resignation where solely personal.
However, the nongovernmental Centre for Investigative Journalism, whose reporters talked to Garlick, has said the Briton left Sarajevo because he did not get a place in the Bosnian State Court's Council for War Crimes. Instead, he was appointed to the Council for Organised Crime and Corruption and was thus put in charge of the Covic trial.
The NGO has said the 53-year-old Garlick has made a successful career in Great Britain as an expert in the fight against money laundering and in extraditions.
His main motive for coming to Bosnia was to gain experience in war crimes trials. Garlick has said he could have tackled organised crime trials in England.
State Court judge Branko Peric, who is also the president of the Senior Council of Judges and Prosecutors in charge, has said he is disappointed with Garlick's resignation.
Peric has said this case clearly shows that some international judges and prosecutors are coming to Bosnia to improve their biographies and not help strengthen the Bosnian judiciary.
Kreso told Dnevni Avaz the immediate consequence of Garlick's resignation would be the delay in the Covic trial, announced for September 1.
She said the contracts of three international judges were about to expire and that their successors would have to be appointed.
Trials before the Council for Organised Crime and Corruption are held before a panel of one domestic and two foreign judges, of whom one presides the panel.
Trials for war crimes, expected to start by the end of the year, will be held before a panel of two domestic and one foreign judge. The panel will be presided by a domestic judge.