Arsenal boss Arsene Wenger lashed out at the referee after his team crashed out of the Champions League last-16 following a 10-2 aggregate thrashing by Bayern Munich.

Wenger was disappointed after Greek referee Anastasios Sidiropoulos denied the Gunners a penalty when they were 1-0 up before later awarding one to Bayern for a Laurent Koscielny foul on Robert Lewandowski.

Koscielny was then red carded as Wenger's side collapsed to suffer a second 5-1 humiliation in two weeks.

"The penalty and red card are absolutely unexplainable and scandalous," said Wenger.

"It's irresponsible from the referee. It leaves me very angry and very frustrated."

Praising his team’s effort, Wenger added that the result did not "reflect the courage of the performance".

"Overall it's difficult to understand what's happened," Wenger said.

"I still must say my team has produced a huge effort tonight and played very well."

Wenger said that Xabi Alonso's first-half challenge on Theo Walcott was "100% a penalty", before claiming that Lewandowski was offside ahead of Koscielny's foul.

He also blasted Sidiropoulos's decision to change Koscielny's yellow card to a red after discussions with the assistant referee behind the goal.

"It's just not serious," Wenger said.

"When you see the importance of the games and you see an attitude like that I am absolutely revolted and sorry for people who come and pay a lot of money to watch this kind of game."

The 67-year-old Frenchman was the subject of a pre-match protest from fans at the Emirates, asking for him to step down.

Asked about the demonstration, Wenger said: "I've nothing to add."