Investigators in the Netherlands have arrested a man and his daughter on charges of sending five million euros ($5.4 million) to Hamas in breach of European Union sanctions, the public prosecutor said Monday.

The 55-year-old man and his 25-year-old daughter, from the town of Leidschendam near The Hague, were arrested on June 22 on suspicion of providing "extensive financing" to Hamas, according to the Public Prosecution Office.

Investigators found the money during house searches in Leidschendam and a commercial headquarters in Rotterdam, and confiscated a bank balance worth about 750,000 euros, according to the Public Prosecution Office.

And it stated that "the Public Prosecution Service is suspected of having sent funds in the amount of approximately 5.5 million euros to groups linked to the Hamas organization."

"They are also suspected of participating in a criminal organization whose goal is to support Hamas financially," it added.

It is suspected that the man and his daughter, who are currently under arrest, had ties to an institution that replaced a sanctioned organization that was sending money to Hamas, according to the prosecution.

She stated that the investigation was opened after reports of unusual financial dealings and after press reports spoke of an event to collect funds in Europe for Hamas.

The European Union included Hamas, which controls the Gaza Strip, on its blacklist of terrorist groups after the September 11, 2001 attacks that targeted New York and Washington.

While a lower court of the European Union removed Hamas from the list in 2014, the bloc's supreme court reinstated it in 2017.