LONDON • Under-fire Arsenal manger Arsene Wenger reacted to his side's humiliating 5-1 Champions League defeat by Bayern Munich on Tuesday by blaming the referee.

Rather than criticise his players for another mauling by the ruthless German side, he directed his frustration at Greek official Tasos Sidiropoulos whose performance he called "scandalous", after Arsenal suffered a 10-2 aggregate defeat in the last 16.

Wenger, out of contract at the end of the season and seemingly edging towards the exit door after nearly 21 years in charge, was angry that Theo Walcott was denied a penalty shortly after his goal had fuelled hope of a miraculous comeback.

And he accused Sidiropoulos of "killing" his side by sending off skipper Laurent Koscielny after the defender had conceded the penalty from which Robert Lewandowski levelled.

"I felt that we produced a performance with spirit and pride that we wanted and after that the story finished badly," Wenger, who has now presided over seven consecutive last-16 exits in the Champions League, told reporters.

"We were unlucky tonight at 1-0 in the first half with a definite penalty on Walcott and in the second half the referee killed the game. After that it was very difficult," the Frenchman added.

"The referee was very powerful tonight. Not only was it not a penalty but (Lewandowski) was also offside. On top of that he gives us a red card that killed us completely.

"I think it was unexplainable, it's scandalous. Bayern are a good side but tonight they can say thanks to the referee."

The 67-year-old cut a forlorn figure as Bayern ran riot in the final 20 minutes with Arjen Robben, Douglas Costa and two goals from Arturo Vidal inflicting their biggest home defeat for 19 years.

"The players did not let me down, the referee let us down," Wenger insisted, rejecting any idea that his players had given up.

"We were in an impossible situation at 1-1 with 10 men, to have to score four goals against a team with their quality. We had no hope."

While Wenger faces up to a troubling end to the season, Bayern coach Carlo Ancelotti remains on course for a triumphant season that could feature a Bundesliga, Champions League and German Cup treble.

The Italian conceded that Arsenal had put Bayern under heavy pressure before the decisive penalty decision.

"Until the penalty, it was difficult for 60 minutes. Arsenal played really well and we made mistakes we don't normally do," Ancelotti said.

"The important thing was to reach the quarter-finals."

Club chief executive Karl-Heinz Rummenigge added: "We would be well advised not to crown ourselves Champions League favourites.

"We were close to letting in a second goal... This should be a lesson for us to remain concentrated and focused."

Arsenal can redeem themselves in this weekend's FA Cup quarter-final against fifth-tier side Lincoln City but even lifting that trophy might not save Wenger.

"We are going through a very difficult situation," he admitted. "What needs to change is a good result at the weekend. We want to focus on that and do our job properly."

REUTERS, AGENCE FRANCE-PRESSE