German police are investigating the use of a drone at Bundesliga club Hoffenheim's training ground ahead of the club's Wednesday's 1-1 draw against Werder Bremen.
Hoffenheim reported on their website that a drone flew over the club's training facilities in the village of Zuzenhausen on Tuesday and that the club had reported the case and alleged drone pilot -- reportedly a Werder Bremen scout -- to the police.
On Thursday, Hoffenheim head of media Holger Kliem told ESPN FC that "an unannounced drone flight" took place and added: "Whoever is responsible for it, over a third-party property or training ground, even more so in darkness, [means that] most of all it is a big security concern and exceeds by far the limit of covertly watching behind a fence."
A Mannheim police spokesperson confirmed to ESPN FC they are investigating the case, saying: "We have an unknown suspect and his car. We are trying to identify him."
Once police are able to identify the suspect, they will then determine whether the use of the drone was permitted by the Drohnen-Verordnung, the German drone act which stipulates that, depending on the weight, certain permissions must be obtained by local authorities.
It also prohibits the use of drones weighing more than 0.25 kilograms over a crowd of people or over inhabited areas where it is not allowed to receive "optical, acoustical or radio signals."
If identified, the suspect could be punished for a Bedeutende Ordnungswidrigkeit, a severe regulatory offence, which under the Luftverkehrsgesetz, the Air Traffic Act, could punishable with a fine of up to €50,000.
Hoffenheim suggested that Bremen sent a scout to try and spy on the training session, but coach Julian Nagelsmann said in his postmatch news conference he was more concerned with the safety of his players.
"If it was someone from Werder or a fan, it's prohibited. You must be careful," he said. "If you fly such things over people and there's a technical defect, it might have serious consequences. If it was someone from Werder. It's normal that you scout the opponent. Everyone does it. I don't mind that. There are just safety concerns."
Bremen confirmed they sent a scout to the training session, which took place behind closed doors, but added they did not order the man to use a drone.
Two drones reportedly flying above London's Gatwick Airport on Wednesday led to a shutdown and severe disruptions in air travel across the United Kingdom. German aviation authorities currently do not collect data over the unauthorised use of drones.