Although the mother and two adult sons have been arrested, the father and adult daughter of the family are on the run – possibly in Venezuela.

In an extraordinary cross-border case, the Dutch authorities have been seeking help from colleagues not only in Germany, but also Belgium, a spokeswoman for Maastricht’s public prosecutor told The Local.

“This is a very unusual case,” she said. “This house of horror was just over the border in Tüddern, Germany – that is where they disposed of the bodies. But at least one was killed in Belgium and the accused family is from Holland.”

The first victim of the family, who she named as 24-year-old Alan Gergeri, said to be from Iraq, was stabbed to death with a knife and an ice pick in 2009.

Dutch newspaper De Telegraaf reported that Gergeri had raped one of the family’s sons.

Two years later, Mohammed al Jader, another Iraqi, was allegedly shot to death by the family, after De Telegraaf said he tried to blackmail them. He was hit by dozens of bullets, the paper reported.

Although at least one of the killings took place in Belgium, the family took both bodies to their house in Germany where they cut them up and dissolved them in hydrochloric acid, flushing what remained down the toilet.

“We were initially following a missing person report, when al Jader was reported missing by his family,” said the prosecution spokeswoman.

“When his body was discovered, it had been almost totally dissolved in acid; there was hardly anything left of him. We also found remains of the other man – so we accidentally found two murders rather than just the one.”

She said that although international arrest warrants had been issued on the fugitive father and daughter, prosecution proceedings would continue against the rest of the family, with a trial expected to start in May 2013.

“It is very difficult to gather evidence in this case, it needs complicated forensic research. We are getting a lot from Germany and Belgium.”

The Local/hc