According to the investigators, a judge at Wuppertal District Court issued an arrest warrant against the suspect. He is thus in pre-trial custody. There had also been searches in several cities against other suspects. The evaluation of the evidence seized in the process is ongoing, according to the authorities. Earlier, the newspaper "Bild" had reported the arrest.

For tactical reasons, the investigators did not want to reveal what was behind the acid attack and how many suspects there were. But it was not a politically motivated attack, said a spokeswoman for the public prosecutor's office. Investigations are under way for serious bodily injury.

According to the news magazine "Focus", the suspect is a member of a well-known rocker group. According to testimonies from witnesses, he is said to have acted on behalf of a competing manager in the power industry. The public prosecutor's office did not want to confirm or deny the report.

According to dpa information, the suspect was arrested at a wrestling tournament in Cologne. This was confirmed by the chairman of the club in which the man is involved in sports.

The Innogy CFO was attacked on 4 March 2018 - a Sunday - after jogging near his home in Haan near Düsseldorf. Two men threw him to the ground and poured acid over him. Günther suffered extremely serious injuries and at times was in life-threatening danger.

He had been taken to a special clinic by helicopter. The case hit high waves nationwide. Günther spent several weeks in hospital and soon resumed his work.

The public prosecutor's office in Wuppertal had initially investigated attempted murder, but the extensive investigations unsuccessfully ceased after six months. Innogy had offered a reward of up to 80,000 euros for information regarding the perpetrators. The company did not want to comment on the turn in the case on Thursday.

In March 2019 - about one year after the attack - the manager made his first public appearance at a financial press conference. The consequences of the brutal attack were still visible to him. He wore tinted sunglasses and a black ribbon around his forehead. "I am happy to be here," he had said. That possibility was "anything but clear a year ago“.

A few days after the attack on Günther it became known that the RWE subsidiary Innogy would be broken up and parts of it taken over by the competitor Eon. Günther had said that Eon's takeover bid had accelerated his return to work.

This was not the first time that Günther had been the victim of an attack. A few years earlier he had also been attacked and beaten up while jogging. So far there are no indications that the suspects were also responsible for the attack further back, said the spokeswoman for the public prosecutor's office.

Four months after the attack, Günther had said in an interview: he had a theory, but "I want to keep it to myself". The attack lasted only a few seconds, the perpetrators said nothing. He then ran home, washed off as much of the acid as possible and dialled the emergency services himself.

(Original text: Frank Christiansen, dpa; Translation: Mareike Graepel)