(Please note: profanity in sixth paragraph)

Slideshow ( 6 images )

ROME (Reuters) - A bloody attack on a journalist has prompted outrage in Italy and put the spotlight on suspected links between extreme right-wing politicians and organized crime in a notoriously unruly seaside suburb of Rome.

A local vote last Sunday in Ostia sent the anti-establishment 5-Star Movement and a center-right coalition to the second-round runoff, but also showed a sharp increase in support for neo-fascist group CasaPound.

The vote is being closely watched as it is the first since the local government was dissolved two years ago by police, who said city hall - responsible for assigning lucrative beach concessions - had fallen under the influence of organized crime.

Ahead of the Nov. 19 run-off, reporters from state TV RAI went to interview Roberto Spada, the brother of an imprisoned mobster, who had expressed support for CasaPound on Facebook and had been photographed with the local candidate.

RAI broadcast video showing reporter Daniele Piervincenzi repeatedly asking Spada, on the doorstep of his gym, whether his family had supported CasaPound and if he thought it could change the down-at-heel neighborhood.

“I don’t give a shit,” Spada eventually replies, before headbutting Piervincenzi in the face and chasing the bloodied journalist with a baton.

CasaPound’s prime ministerial candidate Simone Di Stefano told a news conference the attack was “deplorable” but said the party would not answer for Spada’s behavior as he was not a member. The local candidate said the photo taken of him with Spada had happened to be snapped at a neighborhood event.

RAI said the blow broke Piervincenzi’s nose and doctors had told him he would need 30 days to recover.

Rome Mayor Virginia Raggi tweeted the video, and wrote: “Unacceptable Spada clan violence ... we will stop crime and extremism in Rome.”

Prime Minister Paolo Gentiloni offered Piervincenzi his “solidarity for the brutal aggression suffered in Ostia”, and national police chief Franco Gabrieli said the incident showed the area “still needs substantial work”.

A small player on the national stage, CasaPound won 9 percent of the vote in Ostia, where it hands out food to poor and homeless Italians, compared with 1.8 percent last time.

CasaPound’s Di Stefano challenged the judiciary to investigate whether there had been any arrangements by which votes were exchanged for money or favors in Ostia, adding his group had won between 5 and 8 percent of the vote in three cities since early last year.

“If we had been in some way favored in Ostia by a mafia clan, we would have had a boom there and in the rest of Italy we would have got 0.4. That’s not how it is,” he said.

Spada was detained by police on Thursday and a judge is due to decide on Friday whether to formally arrest him.