AEC costs WA Senate election at $20M

Cost estimates for the West Australian senate election re-run have blown out to more than $20 million.

Australian Electoral Commission officials are in talks with representatives from the Finance Department on how to fund the fresh poll, acting boss Tom Rogers told a Senate estimates hearing on Tuesday.

"The figure that we have been working with finance on is $20 million," Mr Rogers said.

"And that does not include public funding which I think will be in the order of $3 million."

Senator Dean Smith said he thought the cost of the subsequent election had been costed at some $11 million.

Mr Rogers said that was a "back of the envelope" figure provided by then-commissioner Ed Killesteyn during an estimates hearing in November.

"Twenty million dollars. I think that's probably beyond what most electoral enthusiasts ... would have thought," Senator Smith said.

Voters will go back to the polls in WA for a fresh Senate vote at a date to be announced, after 1370 ballots went missing during a recount following the September federal election.