• Hoeness admits to evading tax on an extra €15m • Former West Germany star faces up to 10 years in jail

This article is more than 6 years old

This article is more than 6 years old

The Bayern Munich president, Uli Hoeness, told a tax trial that he hid millions of euros more than authorities thought but denied being a "social parasite".

His defence lawyer Hanns Feigen said that Hoeness cheated the taxman out of €18.5m (£15.4m) – €15m more than the €3.5m listed by the prosecution.

Vowing he wants to come clean on his fiscal wrong-doing, Hoeness told the Munich court that he stashed away the money in a secret Swiss bank account during years of obsessive stock "gambling".

"I am glad that everything is now transparent and on the table," the 62-year-old, who now faces a possible jail term, said on the first day of his trial.

"I deeply regret my misbehaviour. I will do everything to ensure that this distressing chapter closes."

"I have evaded taxes," a rueful Hoeness told the packed court. "I am aware that turning myself in to the authorities does not change that. I was hoping to escape criminal charges with a voluntary disclosure."

Prosecutors argue that his self-reporting of a Zurich account in January 2013 contained irregularities and is invalid because authorities already had Hoeness in their sights at the time.

The former footballer, who also runs a lucrative sausage company, said that during years of stocks trading from 2003 to 2009 that amounted to virtual "gambling", he had lost sight of his gains and losses.

He has earlier told German media that he received a €10.2m loan for trading in his Swiss bank account in 2001 from the late Robert Louis-Dreyfus, then chief of the club's supplier, and major shareholder, Adidas.

He told the court that overall he had ended up in the red after his trading years. He stressed that over the years he had donated a total of €5m , telling the court that "I'm not a social parasite".

Hoeness faces a possible jail term if found guilty by the court, which has scheduled a four-day trial with a verdict expected Thursday.

The maximum punishment for major tax fraud under German law is 10 years jail, but shorter terms, which can be suspended, are more commonly handed down.

He arrived in court Monday through a back entrance and gave photographers a pained smile at the start of the trial in a courtroom packed with media and other audience members.

Public interest in the case has been intense – the 49 allocated media spots to cover the trial were filled within 27 seconds, the court said.

Hoeness has spent more than four decades with the Bayern Munich – first as player, helping win West Germany the 1974 World Cup, then as team manager and, since 2009, as club president.

Despite widespread criticism of Hoeness, his initial offer to resign from Bayern Munich last May was rejected by the supervisory board of the European champions club.

Hoeness has stayed on so far as president, amid expressions of loyalty from fans and players, and support from corporate sponsors such as Adidas, Audi, VW and Deutsche Telekom.

"I can only hope that it turns out well for him and the court shows its human side," said honorary club president Franz Beckenbauer on Sky TV on Sunday.