ATHENS: Two suspected members of Greece's neo-Nazi party Golden Dawn received life sentences on Tuesday over the fatal stabbing of a Pakistani immigrant last year, a judicial source said.

However, the Athens court judging the case threw out the prosecution's argument that the murder of 27-year-old Shehzad Luqman in January 2013 was racially motivated.

Luqman's killing, and that of Greek leftist rapper Pavlos Fyssas a few months earlier, prompted Greek authorities to begin a crackdown on Golden Dawn that revealed the group's violent paramilitary activities, according to investigators.

Several of the party's senior members are now behind bars awaiting trial, with the Greek judiciary gathering evidence to show Golden Dawn operated as a criminal organisation.

Dionyssis Liakopoulos, 25, and Christos Steriopoulos, 29, were arrested a few hours after Luqman's murder when a taxi driver who witnessed the attack reported their motorbike numberplate to police.

According to the driver, the pair drove up behind the victim and assaulted him as he was cycling in the Petralona neighbourhood near the Acropolis.

A search of Liakopoulos's home found Golden Dawn leaflets in addition to knives and truncheons, although the two men have denied membership in the neo-Nazi party.

The pair said they got into an argument with the victim after he blocked their path with his bicycle.

Six of Golden Dawn's 18 elected members of parliament are currently behind bars awaiting trial and a total of nine have been indicted on charges of belonging to, or running, a criminal organisation.

Formerly on the fringe of Greek politics, openly xenophobic and anti-Semitic Golden Dawn has seen its popularity soar as it taps into widespread anger over immigration and austerity reforms in debt-wracked Greece.

The discontent has made the party the third largest in voter intentions, trailing only the conservative New Democracy of Prime Minister Antonis Samaras and the radical left Syriza, the main opposition party.

Golden Dawn entered the 300-seat parliament for the first time after June 2012 elections.