By Mark Lowen
BBC News, Zagreb
**Four men are to appear in court in the Croatian capital, Zagreb, charged with murdering the influential journalist, Ivo Pukanic, in 2008.**The editor of the Nacional magazine, was killed alongside his marketing manager, Niko Franjic, by a bomb in a suspected organised crime attack.
Mr Pukanic was known for investigations into corruption and crime at the highest levels of Croatian society.
The problems could hold up Croatia’s progress towards joining the EU.
EU hopes
Ivo Pukanic swam in dangerous waters - he published frequent investigations into the criminal underworld of the Western Balkans, exposing smuggling and corruption at the highest levels.
He was thought to have close links with some criminals himself, but it is widely believed he fell victim to an organised crime attack and was targeted for what he wrote.
The murder stunned Croatia, revealing the grip of organised crime and corruption.
The authorities are under serious pressure to tackle these issues if Croatia is to fulfil its aim of joining the European Union by 2012.
Four men will now face a lengthy trial in Zagreb, with other suspects currently in custody in Serbia and Bosnia.
On Tuesday, Serbian citizen Bojan Guduric surrendered to the Bosnian authorities in Baja Luka.
Police believe he detonated the bomb.