Amerell has been a referee spokesman for the German FA (DFB) since ending his officiating career in 1994 but resigned from his post several days ago, citing health issues.

Dr Zwanziger confirmed the referee who made the allegation against Amerell sought advice from the DFB, who have since opened an investigation led by the DFB's solicitor Dr Jorg Englisch.

"I returned to my office for the first time after my holidays on January 11 and I was informed during that week by [DFB refereeing panel chairman] Volker Roth on the telephone that a referee had turned to him requesting help," Dr Zwanziger confirmed in a statement on www.dfb.de.

"We summoned Mr Amerell for talks on February 4.

"We are now going to carry on with the necessary discretion and check everything quickly and exhaustively before, based on this, taking the necessary action.

"The DFB is only currently interested in a very careful explanation of the facts. First hearings have already taken place with our chief counsel Dr Englisch and more will follow."

Amerell, 62, was swift to declare his innocence after the revelations became public yesterday, telling DSF television the allegations were "unfounded and made up out of thin air".

DFB vice-president Rainer Koch stepped down from his position in charge of refereeing affairs after claiming he had been the last to learn of the allegations against Amerell.

"Volker Roth, the chairman of the DFB's refereeing panel, was informed personally and at great length about the allegations about Manfred Amerell on December 17, yet he has not to this day informed me, the person who is responsible as a member of the board," Koch said in a press release.

"I first knew about this on Wednesday, February 3.

"This lack of early information from the chairman of the refereeing panel is unacceptable for me."