The Refugee Action Coalition says new search rules at the asylum seeker camps on Nauru make a mockery of claims the camps are open.
In October the Nauru government announced all detainees would be able to move freely in and out of the camps.
A spokesman for the Coalition Ian Rintoul says up to eight women have complained of abusive and humiliating searches by guards at the camp for families and and single women asylum seekers.
"They are subjected to searches in and out of the detention centre. They're not allowed to take anything out, they're not allowed to bring anything in. Smartphones for example are still banned, they're not allowed to bring food or fruit that's bought outside the detention centre. So I mean it's a mockery of the Nauru government's announcement."
Mr Rintoul says two of those women have lodged complaints about Wilson Security guards using security wands in an abusive manner and forcing women to remove clothing in view of male guards during searches.
"Because they are required to spread their legs and their arms, that in itself has provided an excuse for male guards to use those wands in a particularly intimidatory, threatening, humiliating way. By putting the wand between the woman's legs, by passing the wand repeatedly over the breast area, it's very clear from the reports that we've got, the nature of those searches."
Mr Rintoul says he is not satisfied there will be an independent investigation into the complaints.
He says about 200 asylum seekers have not had their claims processed despite the government's October pledge to process all asylum seekers within a week.