Updated

A first batch of lawmakers from the Greek neo-Nazi party Golden Dawn are to be indicted Tuesday on criminal charges as part of a crackdown on the group following the murder of an anti-fascist musician.

Four Golden Dawn MPs, along with a dozen-plus lower-ranking members, will appear at an Athens court on charges ranging from attempted and voluntary homicide to belonging to a criminal organisation.

If convicted, the defendants face sentences of at least 10 years in prison.

"We have a golden opportunity to purge our society of violence," government spokesman Simos Kedikoglou told Skai Radio, calling the group "a criminal organisation that tried to cover itself under a political cloak."

The proceedings opened on Tuesday morning with three Golden Dawn suspects, who were transported to the Athens court complex under heavy police guard.

Other senior members will appear in court later in the week, including the founder of the former fringe party that during last year's elections rode a wave of public discontent over austerity policies in the recession-hit country to enter parliament for the first time.

Golden Dawn was the country's third most popular party until the September murder of a leftist hip-hop musician sparked nationwide protests and a government crackdown on the group long accused of attacking immigrants, charges that it denies.

The investigation has revealed a series of "criminal acts" by the group, culminating in the murder of anti-fascist musician Pavlos Fyssas by a self-confessed neo-Nazi on September 18, according to a government report, parts of which were leaked in the media on Monday.

Golden Dawn regularly organised "assault militias" in which dozens of members would swarm the streets, hitting any immigrant they saw with clubs, it said.

The four MPs due to appear in court on Tuesday include party spokesman Ilias Kasidiaris -- who is alleged to have overseen military-style training for Golden Dawn members -- and Yiannis Lagos, a Piraeus deputy with a lengthy police record.

Greece's intelligence service EYP in 2012 compiled a record on Lagos with activities including extortion and the trafficking of women for prostitution, Ta Nea daily reported on Tuesday.

At the time, the investigation into Golden Dawn activities -- believed to also include scores of migrant beatings -- made little progress.

But authorities were forced to act after the murder of Fyssas sparked protests about the government not acting sooner against the group.

Greek Prime Minister Antonis Samaras on Monday pledged to eradicate the "shame" of neo-Nazism in the country.

"We are dedicated in completely eradicating such a 'shame'," Samaras said in a speech to the American Jewish Committee in New York.

"We must do it within the context of our democratic constitution. But we have to go all the way and do whatever it takes," the premier said, according to a text released by his office.

As part of the sweep against the group, several police officers have been suspended for alleged links to the party, and three have been arrested outright for possible involvement in Golden Dawn activities.

Overall, some two dozen members of Golden Dawn, including six lawmakers, will appear in court this week after a series of arrests and police raids on party offices at the weekend.

The party's leader Nikos Michaloliakos is set to be charged on Wednesday, followed by deputy leader Christos Pappas on Thursday.

The neo-Nazi party started its attacks in 1987, according to the government report leaked in the media on Monday.

The magistrate's report said party members were trained in military-style operations -- including the use of assault weaponry according to reports -- and had allegedly committed dozens of criminal acts.

Emergency legislation has been submitted to parliament to stop the institutional flow of state funds to the party that at the moment has 18 deputies in the 300-member chamber.

Greece's main opposition party Syriza has accused Samaras of dragging his feet in prosecuting Golden Dawn, in order to avoid alienating right-wing hardliners within his own conservative party.