The 850 square kilometers scanned off the coast of western Australia in the hunt for a missing Malaysia Airlines plane are not the "final resting place of MH370," the agency leading the search said Thursday.

The search area is where four acoustic pings originally thought to be from the black boxes of the Boeing 777 were heard in early April.

"The Australian Transport Safety Bureau (ATSB) has advised that the search in the vicinity of the acoustic detections can now be considered complete and in its professional judgment, the area can now be discounted as the final resting place of MH370," a statement from the Joint Agency Coordination Centre said.

Unlikely to be from Flight 370

Hours earlier, a U.S. Navy official told CNN that the pings at the center of the search for the past seven weeks are no longer believed to have come from the plane's black boxes.

The acknowledgment came Wednesday as searchers wrapped up the first phase of their effort in the southern Indian Ocean floor without finding any wreckage from the jetliner.

Authorities now almost universally believe the pings did not come from the onboard data or cockpit voice recorders but instead came from some other man-made source unrelated to the jetliner that disappeared on March 8, according to Michael Dean, the Navy's deputy director of ocean engineering.

If the pings had come from the recorders, searchers would have found them, he said.

Dean said "yes" when asked if other countries involved in the search had reached the same conclusions.

"Our best theory at this point is that (the pings were) likely some sound produced by the ship ... or within the electronics of the Towed Pinger Locator," Dean said.

The pinger locator was used by searchers to listen for underwater signals.

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