The 24-year-old Australian, Jock Palfreeman, will spend his third New Year's Eve behind bars in a maximum security prison in Bulgaria after the travel chaos in Europe delayed his final appeal against his murder conviction.

The appeal trial against Jock Palfreeman's 20-year jail sentence will return to a Bulgarian court on January 19, the fifth day of his appeal hearing, after his father, a key member of the legal defence team, failed to get to the court on December 22 due to the bad weather at European airports.

The delay means the outcome of the appeal is also likely to be pushed back by a month.

The Australian man, sentenced for the murder of 20-year-old Bulgarian Andrey Monov, has pleaded not guilty. He insists he acted in self defence after going to the aid of two Roma, or gypsies, who he says were being beaten by the victim and more than a dozen friends.

Two more key witnesses' statements were re-examined earlier in December as part of the appeal trial, backing Palfreeman's claim about the attack on the Roma.

One more witness, Alexander Donev, a friend of the victim who is understood to be studying in Germany, was heard on December 22 before the court was due to make a final ruling. The young man stood by his own original version, saying he could not recall the exact nature of the incident which occurred before Palfreeman intervened.

Jock Palfreeman has been kept behind bars in a Bulgarian jail after being charged with murder after an alleged street brawl in the capital Sofia at the end of 2007.

According to Bulgarian prosecutors, who asked for life imprisonment for the defendant, Palfreeman was not provoked and did not act in self-defense, as he has claimed.

Palfreeman was also found guilty of attempted murder over the alleged stabbing of a 19-year-old man during the fight.

The Sydneysider has repeatedly denied both charges, saying he was trying to defend himself from being attacked by a group of men.

According to Jock's family, friends and supporters his verdict is a "hideous perversion of justice".