×

Market 'speculator' accused of soccer bus bombing after buying up to $90,000 worth of options

German police have arrested a 28-year-old market trader suspected of being responsible for an attack on the Borussia Dortmund football team.

The man, identified as Sergej W, was arrested early Friday in Tubigen, southwest Germany, after new evidence emerged that he had sought financial gain by causing an explosion on the team's bus, which left two people in need of medical treatment.

The trader, said to be of German and Russian descent, allegedly bought options to short-sell 15,000 shares of stock – estimated to be worth between $83,000 and $90,000 – prior to the attack, which would have enabled him to profit from a drop in the team's share price.

Sergej W was staying at the team's L'Arrivee hotel in Dortmund on the day of the attack, in a room overlooking the street where the explosion took place. The options were purchased via the IP address of the hotel and were linked back to W.

The suspect is believed to have planted three explosive devices in a hedge on the route of the team bus, which exploded 90 minutes before the team were due to play on their home turf on April 11.

Spanish footballer Marc Bartra was treated for wrist injuries and a police officer was treated for shock following the attack.

Borussia Dortmund's stock closed at 5.61 euros ($6.00) before the attack and hit a low of 5.50 euros the next day. Shares later sunk further to 5.36 euros Thursday after being eliminated from the Champions League.

Friday's arrest marks a U-turn on initial calls that the attack was linked to radical Islamism.

Police initially arrested a 25-year-old Iraqi the day after the attack after uncovering letters near to the site of the explosion which claimed links to Islamic State (IS).

However, after examination by Islamic scholars, prosecutors found there to be "considerable doubts" over their authenticity, and said that they may have been created to confuse the case.

Follow CNBC International on Twitter and Facebook.