A weak signal possibly coming from one of two black boxes on board the Air France A330 that crashed into the Atlantic last month has been detected.

The black boxes on the aircraft make a pinging noise for detection, a noise that can be heard up to 1.25 miles (2kms) away. The noise though is only made for one month post a crash, meaning that time is running out in the effort to find the boxes.

The noise story though isn’t confirmed, with some French officials saying off the record that the noise detected wasn’t a black box, and officials have neither denied nor confirmed the story, saying only that no signals have been “validated” yet.

The search for the black boxes includes ships and submarines from the United States, Brazil and France.