A German court on Monday convicted two siblings of money laundering over the illegal sale of ancient Egyptian artefacts, and ordered the confiscation of 32 million euros ($37 million).

The brother and sister, who were not identified, were also hit with hefty fines in the case related to the objects, which allegedly came from illegal excavations in Egypt.

The artefacts, which were sold for millions of euros to museums, included a bust of Cleopatra, a stone slab associated with King Tutankhamun and items from a princess's grave.

Sentencing the pair, a judge at a regional court in the northern city of Hamburg said "unique cultural treasures" were involved in what was a "highly complex legal case".

Illegal trade in artefacts

The man and woman were accused of acting with other suspects, who are being prosecuted separately. The pair are the children of one of the main alleged perpetrators, reportedly an archaeologist from Hamburg.

The male defendant is said to have been involved in illegally trading the artefacts since 2013, according to prosecutors.

He was accused of bringing several sarcophagi from the princess's grave to Germany, having them restored and then reselling them to a museum after concealing their origins.

A few years later, he was involved in the illegal sale of the bust of Cleopatra, Egypt's last pharaoh, and the Tutankhamun slab to museums.

The court ordered the confiscation of 26 million euros from the male suspect, and that he pay a fine of more than 90,000 euros.

He was, however, cleared of the more serious charge of working with a gang to deal in stolen goods, because of insufficient evidence.

Some of the sale proceeds flowed through the account of the female defendant.

The court ordered that six million euros be confiscated from her, and fined her 30,000 euros.