DFB Backs Hoff Boss

The incident happened during Sunday's Bundesliga game which the promoted club Hoffenheim won 4-1 against Dortmund for second place in the Bundesliga standings. Dortmund officials issued an apology to Hopp.

The DFB said in a statement that the criminal investigation in this case was sufficient, but that it will conduct its own probes in the case of future incidents in order to protect Hopp.

"It is no longer enough to call for fairness towards Dietmar Hopp as some of the spectators have not changed their behavior," said DFB vice-president Rainer Koch in the statement.

Hopp said Tuesday he would press charges against the Borussia Dortmund fan who was arrested for displaying the banner threatening to kill him.

A teenage Dortmund supporter was arrested for holding up a poster showing Hopp's face in a crosshair under the message "Hasta La Vista Hopp!" at the Carl-Benz Stadium on Sunday before Hoffenheim's home win.

Police arrested a 19-year-old man from Halbstadt in the central German state of Saxony-Anhalt before kick-off.

German tabloid Bild also reported the fan hurled the insult "son of a whore" at Hopp.

Hopp to press charges

"We will press charges," Hopp, a multi-millionaire, told Bild. "A murder threat is not anything to be taken lightly. This is not something you can ignore and it is important to send out a clear signal that a line has been crossed."

Hopp's lawyer is looking into whether to also launch a civil prosecution against the teenager.

"It is not clear yet whether we can also file a complaint under civil law," Hopp's lawyer Dr Johannes Knorz told Bild. "However, we will press charges because of the insults. The 'whore' insult was bad enough, but the crosshair on the poster went too far."

"What happened was embarrassing, shameful and unbecoming," Dortmund's managing director Hans Joachim Watzke told the tabloid.

The club have said they will do anything they can to help the police investigation.

Hoffenheim owner becoming a target

Hopp was also insulted by Borussia Moenchengladbach fans on the second weekend of the season and the multi-millionaire rarely travels to Hoffenheim's away games.

And the DFB announced Tuesday afternoon they will give Hopp as much protection as they can and will keep a close eye on the behavior of fans in future games involving Hoffenheim.

Vice-president Rainer Koch said: "In future, the DFB will intervene for the protection of Dietmar Hopp and pursue any inappropriate behavior or menaces against him until the perpetrators are caught."

The entrepreneur co-founder of software giant SAP became Hoffenheim's chief backer when they were in the eighth league of German soccer and fulfilled his dream for them to reach the Bundesliga when they won promotion last season.