Immigration Minister Brendan O'Connor has accused the opposition of comparing asylum seekers with pedophiles.
Senior Liberal senator Eric Abetz on Thursday backed calls from his party's immigration spokesman that communities be notified when asylum seekers are released from detention.
His comments come after a Sri Lankan asylum seeker was this week charged with the indecent assault of a university student in Sydney.
Senator Abetz was asked why the government had to inform people about would-be refugees when it didn't inform them about pedophiles who are released from prison.
"There is a register in relation to those sex offenders and the community has spoken in relation to that, that they do want a register," he told reporters in Canberra.
"If I might say, I wouldn't put the two (pedophiles and asylum seekers) in the same category, necessarily."
But Mr O'Connor said the comments were "the lowest form of politics I think I've seen in this country in recent memory".
"To blame thousands of people because of one allegation is the lowest level of politics which I thought could not get any lower, until I saw Senator Abetz today compare people seeking asylum with pedophiles," he told Sky News.
"It doesn't get any lower than that when he compared them with pedophiles and sex offenders and suggesting there should be the same type of register."
The minister called on Opposition Leader Tony Abbott to clarify the comments.
"If he's authorising the shadow minister for industrial relations and immigration to take us down this path, this is a sorry day for Australia," he said.
A spokesman for Senator Abetz denied he was making any links between asylum seekers and sex offenders.
"Senator Abetz's comments this morning were quite clear and claims that he was attempting to do that are totally incorrect," he told AAP.