The asylum seekers climbed onto the roof yesterday.
They told the ABC they fear being deported back to Fiji after another Fijian was sent back last week.
Lawyer George Newhouse, who acted on behalf of the family of 36-year-old Fijian national Josefa Rauluni, who jumped to his death at the centre in 2010, visited the protesters yesterday.
"I am very concerned. What we are seeing is a repeat of the death of Josefa Rauluni in 2010," Mr Newhouse told ABC Radio Australia's Phil Kafcaloudes.
"What you had then was a Fijian man who was being removed, who had been given quite late notice and there were no police negotiators called to the site, and I am very concerned about the safety of these people."
Mattresses have been put around the building in case the asylum seekers decide to jump.
However, Mr Newhouse said that in the past protesters simply jumped over the mattresses to their death.
"Fear of torture"
On Monday, one of the protesters, Sai Bulewa, said he didn't want to return to Fiji because of alleged abuse against homosexuals there.
"Our banner said fear of the torture, fear of the sexual abuse and another banner said we want to live without fear because of the gay rights, we have no rights in Fiji," he said yesterday.
This morning, a spokesman for Australia's Department of Immigration confirmed the three are still on the roof at Villawood.
He would not confirm the reason for their protest and said the department is currently working on the issue.