Uli Hoeness , President of German first division Bundesliga soccer club Bayern Munich, waits in a Munich court room on the second day of his trial. (AP Photo/Sven Hoppe,Pool)

Munich, Germany - The president of German soccer team Bayern Munich, who has admitted evading millions of euros of taxes, hid even more income than he said, a tax inspector told his trial on Tuesday.

Uli Hoeness, a World Cup winning player for West Germany in 1974 who has led Bayern to domestic and European glory, faces up to 10 years in jail in a case that has shocked his club's fans and prompted thousands of German tax dodgers to own up.

As his trial opened on Monday, Hoeness admitted to evading more than five times the 3.5 million euros he had been charged with, around 18.5 million, hoping his admission and apology would mitigate his punishment.

But a tax inspector told the court on Tuesday that documents he had submitted shortly before the trial showed the real amount was 27.2 million euros, a blow for the defence which hoped to show Hoeness informed authorities early and comprehensively enough to avoid jail.

Hoeness told tax authorities in January 2013 that he had evaded taxes, but tax inspector Gabriele Hamberger told the court that her office had waited for more than a year for Hoeness to turn in bank records, despite repeated requests.

A USB stick that the defence gave prosecutors last month contained a document first created a year earlier, she said, indicating it could have been submitted much earlier.

A data expert will appear in court on Wednesday to testify on the electronic documents.

Hoeness made massive profits on the financial markets, earning as much as 30 million euros in some years and held 150 million euros with Swiss bank Vontobel in 2005, Hamberger said.

“We always knew there were documents,” said Ken Heidenreich, a spokesman for prosecutor Achim von Engel, outside the court.

“We repeatedly asked the defendant and his lawyer for the documents. Unfortunately they were only presented just before the trial.”

Hoeness, 62, remains chairman of Bayern and intends to attend Tuesday's Champions League match against Arsenal at Munich's Allianz Arena, just 12 km (7 miles) from the courtroom.

He told the court on Monday he was glad the tax evasion was “all out in the open now.”

“I deeply regret my wrongdoing. I'm doing everything I can to put this unhappy chapter behind me,” he said.

Tax evasion is a serious crime in Germany. Peter Graf, the late father of tennis champion Steffi Graf, was sentenced in 1997 to three years and nine months in jail for evading 12.3 million marks (6.3 million euros). He was released after 25 months.

Hoeness could be sentenced to between five and 10 years in jail if convicted of evading more than 1 million euros in taxes.