Mr Wechsung said that Peter Graf and his associate, Joachim Eckardt, were accused of evading taxes on 42m Marks (pounds 18m) of the world number one's income for the tax years 1989 to 1993.
"The accused are charged with tax evasion in a particularly serious case," Mr Wechsung said in a statement, adding that prosecutors believed the two men had evaded or tried to evade around 19.6m Marks in taxes.
Steffi Graf has also been a target of the massive tax investigation but Mr Wechsung said they had uncovered no evidence so far to suggest she had made any false statements.
"As soon as the investigation into Stefanie Graf is concluded, the public will be informed without delay," he said.
The tennis star has said she knew little about her financial affairs, trusting her father and his advisers.
Peter Graf's lawyers said it was still not clear whether any tax evasion had actually taken place. "Tax law for international athletes is confusing and complicated," they said in a joint statement.
Peter Graf, who has handled his daughter's financial affairs since her childhood, has been in investigative custody in a Mannheim jail since August. Prosecutors have blocked several attempts by his lawyers to get him released, saying he could alter evidence or flee the country. Mr Eckardt is also in custody. Mr Wechsung said the charge sheet was 237 pages long and evidence was contained in 170 folders or files.
Steffi Graf has admitted she may have made mistakes in the handling of her financial affairs but has vowed to stand by her father, a former used-car salesman.
He has undergone psychiatric tests in jail to see if the consequences of years of taking pills and alcohol could allow him to plead diminished responsibility if charges were brought.