Two Italian police officers who were hailed as heroes for killing the Berlin Christmas market attacker, Anis Amri, in Milan harboured pro-fascist sentiments, according to statements and images posted on their social media networks.

Amri, who killed 12 people when he ploughed a lorry into the crowded market, was shot by Luca Scatà and Cristian Movio in the early hours of 23 December. The police shooting was seen as a legitimate act of self defence.

According to a person familiar with the issue, the German government had briefly considered awarding Scatà and Movio a Bundesverdienstkreuz – a national merit award – but declined to pursue the idea after it became aware of the officers’ social media posts.

One year before Scatà, 29, fired the shot that killed Amri, he had posted a photograph on Instagram that shows him performing a Nazi salute, along with the hashtag #romanosaluto or “Roman salute”. The gesture, which was adopted by the Italian fascist party before it was widely practised by German members of the Nazi party, is a criminal offence in Germany.

In another post dated 25 April, the anniversary of the end of Italy’s occupation by Nazi Germany, Scatà posted a notice with the words: “Not everyone carried out the betrayal. Many chose to remain loyal to the flag and give their life for it. I am on the side of that Italy.”

In 2014, Movio, 36, who was wounded in the shoulder during the shootout, posted a picture of a Coca-Cola bottle bearing the name “Adolf” and a portrait of Hitler with the words: “Thanks bro.”

Facebook Twitter Pinterest Cristian Movio in hospital in Milan after the shootout. Photograph: AFP/Getty Images

Both officers shared articles from the xenophobic website tuttiicriminidegliimmigrati.com, listing crimes allegedly committed by immigrants. Their social media profiles were deleted after the Amri shootout.

“Apology to fascism” is technically considered a crime in Italy but it is almost never punished.

A spokesperson for the German interior ministry said it was not aware of abandoned plans to decorate the two men, saying: “In Germany police officers would not be awarded an ‘order’ purely for fulfilling their professional duty.”

The German MP Stefan Mayer, a member of the Bavarian Christian Social Union party, told Bild that if the government had declined to award the officers, the decision was “absolutely correct given their apparent neo-fascist views”.

Experts who follow the Italian far right said some elements within police forces were known to have a “law and order” approach that includes sympathy and support for Mussolini and neo-fascist movements.

Scatà’s father, Giuseppe, told the Guardian: “If the German government has decided [not to honour my son], they can keep their award in Berlin. I don’t care.”

Paolo Amenta, the mayor of Scatà’s home town, said: “We are very proud of Luca. The decision of the German government not to award him is an overreaction. I know Luca since he was a little kid and he was never involved in politics. This decision would be an insult to his courage. It’s an offence against the brave act he did.”

Franco Gabrielli, the Italian chief of police, acknowledged in an interview with Il Messaggero that the social media posts were problematic. He said: “We are aware of the exceptional nature of their gesture [shooting Amri] and also of the nature of what they shared, which can be criticised.”