A Polish MEP is reportedly being investigated by Warsaw prosecutors after he made the Nazi salute during a speech attacking the EU in the Brussels parliament.

Janusz Korwin-Mikke compared the European Union to the German Nazi state during a debate surrounding standardising ticket prices across the EU on Tuesday.

The 72-year-old MEP spoke in English and said that Brussels had adopted a mentality similar to the Nazis.

Drawing on the slogan “ein reich, ein volk, ein führer,” he raised his hand in the notorious salute and declared: “this time it is "ein reich, ein volk, ein ticket".

Prosecutors claim Mr Korwin-Mikke, notorious for declaring that women should be stripped of the vote owing to their lack of intelligence, may have violated Polish law which bans the incitement of racial hatred and promotion of totalitarian systems.

“We have started a process to assess whether there was a public promotion of fascist or other totalitarian systems or an incitement to hatred on grounds of nationality by MEP Janusz Korwin-Mikke,” Pawel Wierzcholowski, from the Warsaw prosecutor’s office, told The Daily Telegraph.

If found guilty, Mr Korwin-Mikke could face either a fine or prison sentence.

Poland’s foreign minister Grzegorz Schetyna apologised for Mr Korwin-Mikke, adding that “we are sorry to Europe, to the European Parliament and to voters.”

It is not the first time Mr Korwin-Mikke has attacked the EU, having previously described it as a "communist project", according to the International Business Times.

Meanwhile, in an interview with The Observer last year, Mr Korwin-Mikke said he wanted to abolish the EU and replace democracy with an absolute monarchy, or at least deny women the vote.