Hamburg - Goalkeeper Jens Lehmann has escaped the wrath of German football authorities following some outspoken criticism of a referee, but two others may not be so fortunate.

The German Football Federation (DFB) said its control panel would be investigating both Borussia Dortmund coach Juergen Klopp and Werder Bremen striker Claudio Pizarro following incidents in the weekend's Bundesliga matches.

However former Arsenal and Germany keeper Lehmann will not be censured despite some harsh words to say about referee Babak Rafati in the wake of Stuttgart's 2-2 draw at Eintracht Frankfurt on Saturday.

Frankfurt coach Friedhelm Funkel was unhappy with a late Stuttgart equalizer which was at first disallowed and then allowed.

"I'd better not say anything about this because I don't have all the money I would need to pay," he said referring to the hefty fine that would probably come his way.

But 39-year-old Lehmann was furious at being shown a yellow card, his fourth of the season, for dissent.

Lehmann picked up the booking after complaining that a Frankfurt player had been feigning an injury which caused the referee to halt a Stuttgart counter-attack.

"When you make so many mistakes it is astonishing that you can be a FIFA referee. We have every reason not to be happy with the performance of the referee. What the man did was incredible," he said.

Describing the yellow card incident, Lehmann said he did not say anything untoward to the referee.

"The referee said he had to stop play for the injury and then the man stands up and doesn't even leave the field to be treated. I told the referee, 'Look! There he goes!' and he shows me a yellow card - incredible," Lehmann told Premiere television.

Lehmann added: "It can't carry on like this, and it's sad for the league. We have to live with decisions on the field but that takes the biscuit."

Lehmann, however, is not the subject of investigation by the DFB because his criticism comes under the category of free expression of opinion rather than that of insulting a referee.

The DFB control panel has meanwhile begun an investigation into Dortmund coach Klopp for alleged unsporting behaviour.

Klopp had run onto the pitch towards referee Jochen Drees after Dortmund's 2-1 defeat at SV Hamburg and was later involved in a dispute with the match official in his dressing room.

The referee, who also sent off Dortmund's Robert Kovac after the final whistle over a remark from the defender, sent a report of the incident to the federation.

Pizarro is facing a similar investigation after comments alleging refereeing bias made in a television interview after Bremen's 0-0 draw at VfL Bochum.

"We played against 12 Bochum players. The referee was a catastrophe," the Peruvian striker said.

The DFB panel has now asked Pizarro for a statement before deciding what further action to take.

For a similar offence, Arminia Bielefeld's Polish striker Artur Wichniarek was last week fined 3,000 euros (3,873 dollars).

After a 3-1 defeat to Bayern Munich, Wichniarek had questioned the neutrality of the referee by saying: "It was 1-1 for a long time, but you can't win here playing 11 against
12. Now everyone is happy - Bayern have won."

The DFB's refereeing envoy Eugen Strigel said the apparent hardening of fronts between players and referees would be a subject for discussion next week at a regular roundtable of referees' representatives and Bundesliga club managers. (dpa)