Federal Labor's campaign for the northern Perth seat of Moore is in disarray, after the party's candidate called immigration detention centres "gulags" on social media and withdrew his nomination.

Moore contains most of the City of Joondalup and is currently held by Liberal MP Ian Goodenough by a 12.4 per cent margin.

WA Labor secretary Patrick Gorman confirmed David Leith was no longer the candidate due to "personal reasons".

Mr Leith officially ceased to be the candidate on March 29, but it is understood Labor made no public announcement at the time.

The ALP has deleted Mr Leith's official Labor Facebook account and removed all his links to the federal election campaign. However, the comments are still visible on his personal Facebook page.

The party is now scrambling to fill the position and said it would announce a new candidate in the coming weeks.

Mr Leith's departure is the second blow for Labor in as many weeks, after Fremantle candidate Chris Brown was dumped for not declaring spent convictions from the 1980s.

In the June 2015 post, Mr Leith likens immigration detention centres to gulags.

"There is no rationale on security or other grounds for the concentrated internment of refugees," he said in the post.

"Refugees are held in detention for what are essentially political reasons - for demonstration or exemplary purposes - which means Australia is possibly the only state to hold civilians, including children, as political hostages.

David Leith's post on his Facebook page comparing immigration detention centres to gulags. ( Facebook )

"It also means that Australian immigration facilities are essentially a gulag for the arbitrary incarceration of non-citizens who have committed no crime, whose only error has been to fall into the hands of the Australian authorities.

"It's now very clear that once taken by Australian military or paramilitary forces, State policy requires that refugees will either be trafficked into captivity in Indonesia or they will be held as political captives by Australia or one of its clients."

Mr Leith also shared an online petition he had signed supporting Human Rights Council head Gillian Triggs, urging the then-Abbott government to cease "playing the man" on the issue.

Mr Leith has been contacted for comment.