The father of a young Bulgarian man, who was stabbed to death by Australian Jock Palfreeman in a 2007 street brawl in Sofia, has slammed the Aussie as "a sociopath on a murder quest".

"My son just had the bad luck to meet a sociopath, who came from the other end of the world to kill people in the center of Sofia, on a holiday night. Nobody could have predicted this," Andrei's father, famous Bulgarian psychologist Hristo Monov, said in an interview for local 24 Hours daily.

Asked who he views the tragedy nearly four years later, Monov said this was just a tragic coincidence of events, which claimed the life of a young man, who had ambitious goals and put in lots of efforts to achieve them.

"Andrei was raised to believe that a man is as big as his dreams and dreams can come true only if you work hard, respect the other people and life itself."

Andrei Monov, a 20-year-old Bulgarian law student, died in the early hours of December 28, 2007 after he was fatally stabbed by young Australian Jock Palfreeman in a street brawl in the center of Bulgarian capital, Sofia. Another man, Antoan Zahariev, was wounded.

Palfreeman was convicted in December 2009 to twenty years in jail, a sentence that he and his parents appealed, slamming it as "hideous perversion of justice".

A three-member panel of the Sofia Court of Appeals at the end of February upheld on all counts the verdict of Sofia City Court. The judges declared Australian citizen Jock Palfreeman guilty and sentenced him to 20 years in prison for the murder of Andrei Monov.

In addition to his jail sentence, Palfreeman must also cover the court costs of his appeal. He must also pay BGN 450,000 (USD 311,000) in compensation to Monov's family and BGN 50,000 to Zahariev.

The ruling is subject to appeal at the Supreme Cassation Court.

The Australian Jock Palfreeman, who has already challenged the ruling at the supreme court, argues that he intervened only to go to the aid of two Roma gypsies being beaten by the group of boys, part of which Andrei was.

The parents of Andrei will launch an appeal of their own, demanding that Jock gets the heaviest sentence in Bulgaria – life without parole.

Ever since the tragic incident Andrei's friends and family have been shying away from the media, barraged by what they have described as "the media performances" of the murderer and the one-sided coverage of the Australian media, who prefer to picture Jock as nothing but a victim of a judicial farce.

Jock's appeal was built upon the discrepancies between the initial statements of the witnesses and the trial evidence, a faux pas, which he attributes to their efforts to cover up the initial clash with the Roma.

The Australian claims he pulled out the knife only after he saw a group of men beating an unidentified Roma person for up to 40 seconds.

Jock Palfreeman also wants his original murder conviction overturned on the grounds that the legal process was deeply flawed. According to him the original court decision and the whole trial and case has been flawed and wrong, marred by procedural lapses, discrepancies in evidence and intentional oversights.

The defence has harshly criticized the police for failing to secure the crime scene, get CCTV footage and call in front of the judges all the important witnesses.

The Bulgarian appeals court however has ruled that the Australian's right to a fair trial has not been breached.