Beckenbauer, who led the organising committee for the World Cup in Germany and had said he had done the work on a voluntary basis, received 5.5 million euros (4.70 million pounds) from a deal involving event sponsor Oddset.
He was not being paid by betting company Oddset but through the DFB.
"It was known that Franz Beckenbauer had been active in advertising for Oddset during the 2006 World Cup. It was not known to us that he received the noteworthy sum of 5.5 million euros out of the organising committee pot," Grindel told reporters.
"With this background, one can certainly not claim that his activities within the organising committee were on a volunteer basis," Grindel, speaking on the sidelines of a UEFA meeting in the Greek capital, said.
Beckenbauer, who also faces a criminal investigation over the awarding of the World Cup, was not available for comment.
His lawyers said in a statement the DFB was well aware of the contract and there was nothing hidden, with Beckenbauer being paid a percentage of the revenues for a contract he delivered to the DFB.
The former World Cup winning coach and player appeared in adverts for Oddset during the tournament but had always insisted his work for the organising committee was unpaid.
Grindel took over in April following the resignation of his predecessor Wolfgang Niersbach late last year over another World Cup 2006 scandal.
"For me this frustrating issue is more proof the organising committee of the World Cup wanted to block out things, that there was no transparency there and that the public was partly misled," Grindel said. "I condemn that."
BECKENBAUER DEAL
Lotto Bavaria said in a statement neither Oddset nor the German lottery administration had any contract with Beckenbauer.
"As a result there was no fee agreement or fee payment. The contractual partner of Mr Beckenbauer was the DFB," it said.
"The lottery administration signed a contract (with the DFB) in August 2004 as a national backer for the 2006 World Cup. Mr Beckenbauer received the advertising fee from the DFB."
Beckenbauer is already under investigation by Swiss authorities, who have opened criminal proceedings against him and two former presidents of the DFB in connection with its successful bid for the 2006 World Cup.
The Swiss Attorney General's office said the proceedings relate to allegations of fraud, criminal mismanagement, money laundering and misappropriation.
Earlier this year, the DFB commissioned a report into alleged irregularities over the awarding of the World Cup.
The report said that, while there was no evidence of Germany paying world soccer's governing body FIFA members in return for votes, payments were made to at least one former FIFA official.
These were made through a web of accounts involving several other firms or individuals, including Beckenbauer.
Beckenbauer, who captained West Germany to the 1974 World Cup title and was coach when they won again in 1990, has previously admitted to making mistakes but has repeatedly denied any wrongdoing.
(Editing by Amlan Chakraborty and Ian Chadband)
