The suspect was arrested by a German federal anti-terrorist unit in the state of Baden-Wurttemberg on Friday morning and has been charged with attempted murder, causing an explosion and aggravated battery, an official press release said.

The Federal Prosecutor's office in Germany says the man is suspected of having acted for financial reasons and had speculated on Dortmund's share value dropping after the attack.

The statement added that the suspect had booked a room in Dortmund's team hotel from April 9 through to April 13 and April 16 through to April 20, the time-frame during which a second leg would have been played at Dortmund had their Champions League quarterfinal draw necessitated it.

The Federal Prosecutor's office in Germany added that the three blasts detonated at the time the bomber had intended, but that the second blast occurred around one metre above the ground, limiting the damage.

The bombs were filled with metal pins around 70 millimetres long, with one pin found 250 metres away from the blast.

Borussia Dortmund's bus was stopped after a series of explosions that shattered windows last week.

Investigators from the Federal Prosecutor's office in Germany, the Federal Criminal Police and North-Rhine Westphalian state police had been following the lead after receiving information from the finance sector as well as from a bank suspecting money laundering, according to Spiegel, which broke the story early on Friday.

Last Tuesday, three explosions near the Dortmund team bus injured two people, including BVB defender Marc Bartra, and investigators later said that the attack could have caused major harm.

It was confirmed on Friday that one metal pin was found in the headrest of one of the seats in the last row in Dortmund's team bus. According to earlier reports, Bartra sat in the last row along with goalkeeper Roman Burki.

Following the attack, three identical letters were found near the scene of the attack and suggested a possible Islamist extremist motive, but investigators had doubts about their veracity. The Federal Prosecutor's office repeated on Friday that there are "strong doubts over a radical Islamist background" of the attack.

It added that another letter claiming the attack for a far-right background received by Berlin-based daily Tagesspiegel on April 13 also raised doubts, and could not be linked to the person behind the attack.