A Spanish court on Tuesday acquitted 13 members of the Hells Angels biker gang on the holiday island of Mallorca who were accused of organized crime, including the chapter's German leader.

A total of 45 people went on trial in January at the National Court in Madrid for allegedly belonging to a criminal organization that was involved in activities such as pimping, extortion, drug trafficking and acquiring illegal firearms between 2009 and 2013.

The main accused was German national Frank Hanebuth, who rose through the Hells Angels ranks in Hanover before allegedly founding the Hells Angels chapter in Mallorca and then appointing its members.

Prosecutors had sought a sentence of 12 years for him but the court acquitted him of all charges, saying it had not been proven that he set up the Mallorca chapter of the Hells Angels to carry out "the alleged criminal activities" that were investigated.

During the trial Hanebuth denied the Hells Angels chapter was a criminal organization and said he had no working relationship with the other suspects, adding he only traveled to Mallorca to spend the summer holidays.

The court absolved all defendants of belonging to a criminal organization, saying this had not been proven.

The court did however sentence 32 of the accused to jail terms of up to two years for lesser crimes, most of them after they entered into plea deals with prosecutors.

Among them was Hanebuth's alleged right-hand man, Paul Engelke who was sentenced to one year and six months' imprisonment for making threats.

Under Spanish law, prison terms of under two years can be suspended provided there are no previous convictions.

Spanish police shut down the Mallorca chapter of the Hells Angels in 2013. It was made up of people from across Europe, mainly Germany, as well as Turkey.

The Hells Angels club was founded in California in 1948. It now has members around the world who are known for favoring Harley-Davidson motorcycles and wearing denim and leather.