An internal police inquiry has been launched in Belgium after claims that police officers and soldiers held an orgy during last month’s terror lockdown.

According to reports two policewomen and eight soldiers allegedly held a sex party at a police station in the Brussels neighbourhood of Ganshoren while the authorities hunted for terrorists in the wake of the Paris attacks.

Soldiers slept at the police station for two weeks during the operation. "When they left, they organised a small party to thank the police in the area," a police spokesman told Belgian newspaper La Derniere Heure. "We have launched an investigation to find out what exactly happened."

Speaking to another newspaper, the spokesman said 15 to 20 soldiers had been sleeping at the Ganshoren police station during two weeks in November so they did not have to travel so far at the end of their shift.

The police station was near Molenbeek, where anti-terror raids had been taking place.

The spokesman said an internal investigation was launched after allegations of an orgy were reported by La Derniere Heure on Tuesday.

Brussels remained on lockdown for a number of days after 130 people were killed by ISIS militants in Paris.