Labor has won just a single West Australian Senate seat while the Liberals have secured three spots in the re-run election.

The results of the recontested poll, which was held on April 5, were announced by the Australian Electoral Commission (AEC) in Perth on Tuesday afternoon.

The new senators-elect are Liberals David Johnston, Michaelia Cash and Linda Reynolds, the ALP's Joe Bullock, the Greens' Scott Ludlam and Dio Wang from the Palmer United Party.

Results from last September's Senate election were declared void when about 1,400 ballots disappeared during a vote re-count, forcing a re-run of the poll.

The AEC promised improved procedures in the wake of the vote loss but it again came under fire after 75 pre-poll votes were ruled invalid because of a ballot box problem at a Perth retirement home, forcing the residents involved to vote for a third time.

The fresh election attracted a record 77 candidates including a host of new micro parties.

The original vote was declared void by the High Court because of the missing votes.

A re-count was ordered because of the close result which saw Mr Wang and Senator Pratt lose out to Senator Ludlam and the Australian Sports Party's Wayne Dropulich.