By Mark Lowen BBC News, Athens
Golden Dawn has recently been riding a wave of support
A fortnight ago, Golden Dawn was feeling smug. Greece's neo-Nazi party was riding high in the opinion polls at about 15%, double what it got in last year's election.
Its support was soaring among a nation buckling under its worst financial crisis in living memory. It had opened new offices, lectures it hosted presenting the party's view of Greek history were proving popular, its 18 MPs appeared untouchable.
But Pavlos Fyssas changed all that. A left-wing hip hop musician and activist, he had spent the evening watching football on TV in a bar near Athens. As he left, he was set upon by a group. The man arrested for stabbing him to death confessed to being an active supporter of Golden Dawn.
The murder prompted a national outcry. Tens of thousands took to the streets, demanding that the violent neo-Nazis be reined in.
Some of Golden Dawn's arrested MPs have been released pending trial
And then, in a weekend morning raid, the government sprang into action. Some 22 members were arrested, six of them MPs, including the party leader Nikos Mihaloliakos. They were charged with belonging to a criminal group, with counts including murder, assault and money-laundering.
'Offer of violence'
Police say they found evidence linking the killer of Pavlos Fyssas to the Golden Dawn leadership. In the homes of MPs arrested, they said they uncovered photos of Adolf Hitler and swastika flags. Witness testimony told of a "Fuehrer-like" party structure, commanding hit squads that drove through Athens attacking migrants.
Whistleblowers are now under police protection. But we traced a former supporter who offered us a rare insight into how the party functions.
She attended Golden Dawn meetings looking for support, after being harassed by a man.
"Inside, I saw clubs and shields," she tells me. "Everyone stood to attention when the leader came in. They talked of beating up gay and dark-skinned people."
She lights a cigarette and holds back the tears.
"A party member came to visit me," she says. "He made me an offer: he could break someone's arm and leg for 300 euros [£250]. Set a car on fire for 1,000 euros. Put someone in hospital for a month for 1,500 euros.
"I didn't want any of it, so I broke off communication. Later he came back and told us not to say a word or he'd burn us alive."
So why, when the party's vigilante nature was well known, did the authorities not act sooner?
We have no involvement in the killing of Pavlos Fyssas. You can buy a T-shirt for 10 euros and you can stab anyone you like. So does it mean Golden Dawn is responsible for your actions?”
Artemios Mathaiopoulos Golden Dawn spokesman
Greece's Racist Violence Reporting Network found that in 2012, there were 154 cases of racist attacks and, so far this year, 104. Two immigrants were murdered. Almost every incident is attributed to Golden Dawn.
One theory for the failure to act against this is the alleged collusion of the police. In last year's election, figures from some areas of Athens suggested that one in every two police officers voted for Golden Dawn.
Several high-ranking members of the force have been suspended in the recent clampdown on the party, with others resigning.
Footage filmed by the website info-war.gr showed men in plain clothes standing close to riot squads policing an anti-fascist demonstration two weeks ago, hurling rocks at the left-wing activists. At least one of the men has been identified as a Golden Dawn member.
Amateur video from info-war.gr shows alleged Golden Dawn sympathisers clashing with left wing protesters in Athens
We met a Pakistani immigrant stabbed three times by suspected Golden Dawn supporters. A year on, the scars are still there - one just millimetres from his heart. On his stomach is a lump of scar tissue from the second wound, which has never healed.
But, he says, the police did nothing, launching no investigation and never contacting him beyond a first conversation.
"It's because I'm a foreigner", he says. "The police never act with us. If it were a Greek who got stabbed, they'd hunt the aggressor immediately. Now I'm terrified to go outside.
"I want to leave Greece for somewhere safer, like England."
A Pakistani immigrant survived being stabbed close to his heart
But the government has defended itself against charges of dragging its feet. The Minister for Public Order, Nikos Dendias, says the murder of Pavlos Fyssas was the first time that a clear chain of command could be drawn to the highest echelons of Golden Dawn.
"Any citizen or head of a political party could report Golden Dawn to the supreme court to have it classified as a criminal organisation," he tells me.
"The fact that nobody did until now shows there was not enough proof."
I put it to him that he had appeased Golden Dawn for the last year so as to push through the government's crackdown on illegal immigration. And that it had taken the killing of a white Greek citizen for authorities to spring into action.
"I totally reject that," he says. "Criminal files have been opened in all the cases until now. But to claim that a criminal organisation was created, you have to have very clear evidence. When that came, we acted. And we took a huge political risk."
Beginning of end?
It is a risk that appears to be paying off. For the first time since the election, Golden Dawn has dropped significantly in the opinion polls - down to about 6%. Daily revelations about weapons found in suspects' homes should, the government hopes, turn the public mood against the party.
But its acting spokesman, Artemios Mathaiopoulos, remains defiant. "We are a political movement that has no relation to crime", he tells me outside police headquarters. "We have no involvement in the killing of Pavlos Fyssas."
I put it to him that police found Golden Dawn clothing and other items in the assailant's home.
"You can buy a T-shirt for 10 euros and you can stab anyone you like. So does it mean Golden Dawn is responsible for your actions?"
Is this the beginning of the end of his party, I ask?
"It's the beginning of the end of the government", he proudly replies.
But Greece's neo-Nazi party is in chaos. Decapitated of its leadership, on the back foot and facing a barrage of damaging disclosures, it is hard to see Golden Dawn being able to fight back.
That said, it still has a significant support base among Greeks exhausted by the financial crisis, revolted by the political mainstream and seeing salvation in ultra-nationalism.
The government can crush the party structure, but removing its ideology and bringing its supporters back from the extreme will be the real challenge.