german government had planned an amnesty for tax evasion as long as they pay the evaded taxes.
Hoeneß waited for that, but then the second chamber of german parliament stopped the amnesty.
At the same time german tax authorities were buying CDs with all kind of information on secret bank accounts in Switzerland on the "black market" from former swiss bank employees, who had stolen the data from their banks. It was just a matter of time, when Hoeneß name would have been on one of these CDs.
Self-indictment was the only way he could get away with it under certain circumstances. But the prosecutors now claim it was too little too late.