Borussia Dortmund: Bus attack suspect took out five-figure loan to bet on German team's stock dropping

A German-Russian man has been charged with carrying out last week's attack

Three explosions went off nearby Dortmund's bus, shattering windows (Getty)

The suspect in the Borussia Dortmund bus attack took out a five-figure loan to bet on the stock drop caused by last week’s bombing, German prosecutors have confirmed.

A German-Russian man was been arrested by police in the early hours of Friday morning following a raid by a police tactical response unit in the Tuebingen area, 30km south of the city of Stuttgart and 450km south of Dortmund, and accused of carrying out the bombing of the Borussia Dortmund team bus ahead of their Champions League quarter-final first leg last Tuesday.

The man, identified only as Sergej W under German law, has been charged with attempted murder, causing an explosion and serious bodily harm after three bombs exploded next to the bus, leaving Dortmund defender Marc Bartra with arm injuries that required surgery and also injuring a policeman.

After questioning the validity of a letter found at the scene that claimed Islamist extremists were responsible for the attack, prosecutors have since said that the man being held carried out the attack for financial gain after purchasing shares in the club, hoping to sell them after a price drop at a pre-determined figure.

"We are working on the assumption that the suspect is responsible for the attack against the team bus of Borussia Dortmund," prosecutors' spokeswoman Frauke Koehler said on Friday.

The man came to the attention of investigators because he made "suspicious options purchases" for shares in Borussia Dortmund, the only Bundesliga club listed on the stock exchange, on the same day as the 11 April attack.

He took out a loan of "several tens of thousands of euros" days before the attack and bought a large number of so-called put options, betting on a drop in Dortmund's share price, she said.

"A significant share price drop could have been expected if a player had been seriously injured or even killed as a result of the attack," according to prosecutors, though Koehler said the precise profit W. might have expected was still being calculated.

The top security official of the North Rhine-Westphalia state, Ralf Jaeger, said that the attack was fuelled by a financial motive. “The man appears to have wanted to commit murder out of greed,” said Mr Jaeger.

Frauke Koehler added that there are "no indications of possible helpers", although the investigation into whether he had any accomplices will continue.

The suspect will appear in court on Friday where it will be decided if he should remain in custody.