BRISBANE, Nov 26 AAP - The Australian Democrats will move a motion in federal parliament calling for a judicial inquiry into the Siev-X incident.

Democrats leader Andrew Bartlett tonight committed his party to the motion which would allow an independent judge the power to subpoena testimony.

The announcement in Brisbane followed a similar call by former Australian ambassador Tony Kevin.

A total of 353 mainly women and children asylum seekers died on a 19-metre wooden boat after it sank in international waters on October 19 last year.

A senate inquiry into the incident earlier this year was unable to subpoena key witnesses, including that of former defence minister Peter Reith.

Senator Bartlett said while the senate could not establish a judicial inquiry itself, it could put pressure on the Howard government to do so.

"We'll look to get a motion passed through the senate calling for the establishment of a judicial inquiry," Senator Bartlett said.

"The senate itself can't establish one - it doesn't have the power but we're trying to use that to increase the pressure on the government to establish one.

"I think there is clearly a responsibility there and there are more and more unanswered questions and it seems this will be the only way to clear up the issue once and for all." - AAP