Boys were shown on the video being shot in the back

The video was first shown last week as evidence in the trial of former Serbian leader Slobodan Milosevic.

Croatian police said the suspect was arrested on Sunday in the village of Banovci, near the town of Vukovar.

Several of those thought to appear in the video have been arrested in Bosnia and Serbia in recent days.

The suspect arrested in Croatia is a 52-year-old Croatian national, police said, but he has not been named.

He is alleged to have been a member of the Serb paramilitary unit, the Scorpions, which is said to have taken part in the Srebrenica massacre.

Still at large

In July 1995, about 8,000 Muslim men and boys were separated from their families in the Bosnian town of Srebrenica, and killed.

It was the worst atrocity in Europe since World War II.

The video footage showed six teenaged boys, their hands bound, being led from a truck and shot in the back.

The event had been captured by a Serb soldier, but had never been seen before in public.

The video has shocked Serbs, some of whom had previously refused to accept that the massacre took place.

The two men accused of ordering Srebrenica, and indicted with genocide - Bosnian Serb leader Radovan Karadzic and his military commander, General Ratko Mladic - have still not been caught.