But not this week.

The couple are in Sofia, Bulgaria, where Dr Palfreeman's son Jock has been in jail since late December 2007.

Jock, 21, is facing murder and wounding charges after a fight in a Sofia street. The dead man, Andrei Monov, 20, died from stab wounds on the way to hospital.

Jock admits to wielding the knife but says it was self-defence.

In an interview with ABC Television's Foreign Correspondent program, to be aired on Tuesday, he says he went to the rescue of some Gypsies who were being beaten up by a gang.

The prosecution disagrees with his version of events and is calling for a life sentence without parole.

Jock went to school at Sydney's St Ignatius' College, Riverview, at Lane Cove.

The Jesuits at Riverview teach under the Latin motto "Quantum Potes Tantum Aude", which can be translated to mean "dare to do, as much as you can" or "strive your hardest".

Jock's apparent willingness to stand up for an underdog and his resemblance to movie idol Matt Damon have helped to turn him into something of an underground hero, with a vigorous debate on Facebook over the morality of his actions.

In Bulgaria, Andrei Monov's death has become something of a cause celebre, at least partly, it seems, because he came from a prominent family.

Attention has turned, too, to confirmation by NSW police that Jock Palfreeman was questioned, although not charged, over an alleged stabbing at a Chatswood party in 2004.

Dr Palfreeman says he knows his son is "impetuous and so on".

"But the more I'm with him and see him handling the situation, the more proud I am of him and the more he's actually giving me some strength and courage to continue on as well," Dr Palfreeman said.

Dr Palfreeman is a medical director for pathology company Douglass Hanley Moir, running its Newcastle, Port Macquarie and Taree operations.

Neighbours said he moved to Honeysuckle from Sydney less than a year ago, and that they were wishing him well.

Dr Palfreeman's uncle, Stephen Palfreeman, of Hickeys Creek, west of Kempsey, said he knew his great-nephew was "no thug".

He said Dr Palfreeman had made a number of trips to Bulgaria.