Australia’s war on refugees reached a new low this week when it was revealed that Australian officials were secretly screening out asylum seekers who were still at sea via videolink, and likely handing them back to the countries from which they fled.

Australia’s conduct on refugees has often pushed the bounds of its international obligations, but refoulement of refugees is an outright breach. The UNHCR has expressed “profound concern” about our handling of these latest boats, carrying Tamil asylum seekers from Sri Lanka.

But what does this mean in a practical sense? Who has the power to challenge Australia in an international court, and how likely are they to do it? International law expert Ben Saul explains today.

Meanwhile, Greg Lake, a former senior immigration department official, told Guardian Australia on Wednesday that the department had considered this “mothership model” — where asylum seekers are processed on-water before being taken back to the country they fled, or to Manus Island or Nauru — as early as 2012.

“The reason it didn’t happen is the senior counsel for the department advised it was not legal to hold a person in a mothership situation, because when you detain a person your primary reason for detention has to be to take them to a detention facility. We couldn’t justify sitting them in a mothership,” Lake said.

If asylum seekers are indeed being “processed” at sea under a system that does not meet our international obligations, then the public servants involved have a moral duty to reveal it, given the government steadfastly refuses to offer any acknowledgement of its actions.

Crikey calls on all public servants who witness these actions to speak out.