A 28-year-old man has been charged in relation to the attack on Borussia Dortmund's team coach, the Federal Prosecutor's office in Germany has confirmed.

The suspect, identified as 'Sergej W', is of dual German and Russian nationality and has been charged with attempted murder, causing an explosion and inflicting dangerous bodily harm.

Letters found at the scene of the crime with apparent "links to so-called Islamic State" initially prompted police to focus on "two suspects from the Islamist spectrum", but the Federal Prosecutor's office alleges that 'Sergej W' was motivated by financial gain after buying 15,000 shares in the club.

"If the shares of Borussia Dortmund had fallen massively, the profit would have been several times the initial investment," a statement said, before adding that such a slump would have occurred if players had been seriously injured or even killed.

The suspect booked a room at the same L'Arrivee hotel where Dortmund players were staying, between the periods April 9 to 13, and April 16 to 20, with it unclear at the time of booking when Thomas Tuchel's men would be playing their home tie, and had a room overlooking the street where the explosions occurred.

Three blasts took place as the bus was travelling to Signal Iduna Park for the Champions League quarter-final first leg against Monaco on April 11, with defender Marc Bartra requiring surgery on his right wrist as a result of the attack.

The incident caused the match to be postponed by a day.