Prosecutors in Rome have launched a murder investigation after a leading member of Lazio Ultras, hardcore football fans often associated with the extreme right, was shot dead in a park in Rome.

Fabrizio Piscitelli, 53, was shot in the back of the neck in broad daylight on Wednesday in Acqueduct park, in the Cinecittà area of the capital.

Nicknamed Diabolik (diabolic), he appeared to have been the victim of an execution-style hit, according to reports. One theory circulating in the Italian media is that Piscitelli’s killer was waiting for him on a bench, having lured him into a trap.

Investigators are also exploring the possibility an organised crime group was behind the killing. Piscitelli had a criminal record for drugs trafficking and in 2016 police seized €2m worth of his assets.

“Piscitelli had lots of enemies and lots of business with various criminal groups,” police sources told Ansa news agency. The sources described Piscitelli as a “central figure” with links to a range of criminal groups, including the Albanian mafia. Flower tributes have been left on the park bench where his body was discovered.

The Lazio Ultras, also known as Irriducibili (irreducible), have been behind several acts of racism and antisemitism that have blighted the Serie A football club in recent years.

In April they paid tribute to the fascist dictator Benito Mussolini in Milan, before an Italian Cup match between Lazio and AC Milan. Two AC Milan players were also subjected to racist chants by fans during the game.

In October 2017 the Ultras covered Rome’s Olympic stadium with stickers featuring Anne Frank wearing the shirt of their rivals, AS Roma, alongside an antisemitic message. Thirteen Lazio supporters received stadium bans of between five and eight years and the club was subsequently fined €50,000.

Last year the group, which was created in the 1980s, distributed leaflets outside the Olympic stadium suggesting women should only be able to sit or stand at the back of the stadium.