Investigators have been looking for missing Malaysia Airlines Flight 370 for one month now and have little to show from it, aside from a lot of false alarms and a hefty price tag that puts the search for MH370 on track to be the most expensive rescue effort in aviation history.

Reuters reports that the search has cost participating countries — mainly Australia, China, the U.S. and Vietnam, which have all sent military ships and aircraft to scan the Indian Ocean and South China Sea for traces of the plane — at least $44 million so far. That figure, however, is likely to balloon before the search is done, per Reuters

The bill for the current search is expected to run into hundreds of millions of dollars. The $44 million estimate for MH370 does not cover all the defense assets being used by countries including Britain, France, New Zealand and South Korea, nor numerous other costs such as civilian aircraft, accommodation for hundreds of personnel and expenses for intelligence analysts worldwide.

Australia, which has taken the lead since officials shifted the search area to a region off the coast of Perth, has spent roughly half the total on the search. Prime Minister Tony Abbott, who has repeated a commitment to continuing the search, said last week that "It's only reasonable that we should bear this cost - it's an act of international citizenship," but added that:

At some point, there might need to be a reckoning, there might need to be some kind of tallying, but nevertheless we are happy to be as helpful as we can to all the countries that have a stake in this.

The Pentagon said last week it has so far spent $3.3 million on search efforts. China didn't say how much the search has cost their nation, but based on the amount and caliber of ships and planes it has been sending out, Beijing is also sparing no expense. And unconfirmed reports suggest that Vietnam has spent somewhere around $8 million.

It's not surprising that the cost of the search has racked up so quickly, searchers have shifted direction multiple times and sent out increasingly sophisticated search technology as time passes. Yesterday, a submarine was sent out to search the area were pings possibly emanating from plane debris were picked up. And as each country pledges to continue looking, no end is in sight. Just today, Australian search coordinator Angus Houston said “There have been no further contacts with any transmission."

But Houston remained somewhat hopeful, adding "we need to continue that for several days, right up to the point at which there’s absolutely no doubt that the pinger batteries will have expired... We’re very hopeful that we will find further evidence which will confirm the aircraft is in that location.”