"I can confirm that what we found was the tail part from the pictures," Bambang Soelistyo, the head of Indonesia's search and rescue told reporters in Jakarta, adding the search team "now is still desperately trying to locate the black box".
"I can ensure that this is part of the tail with the AirAsia mark on it," he said.
The tail section was found 30 kms from the plane's last known location. The tail is where the black boxes are located. The black boxes are considered the key piece of evidence when it comes to investigating a commercial plane disaster as they provide valuable information, from a plane's air speed to the position of the landing gear, to pilot communications.
The tail was identified by divers after it was spotted by an underwater machine using a sonar scan, Soelistyo said.
More From This Section
No survivors have been found while 40 bodies have been recovered so far but officials believe most of the remaining bodies could still be trapped inside the plane's fuselage.
Soelistyo said divers were preparing to go back underwater in the same area, which is in one of the priority zones where search efforts have been focused.
Powerful currents and murky water continue to hinder the operation, but searchers managed to get a photograph of the debris about 9 kms from where the flight lost contact after it was detected by an Indonesian survey ship, he said.
AirAsia group chief executive Tony Fernandes confirmed the announcement in a post on his Twitter account.
"I am led to believe the tail section has been found. If right part of tail section then the black box should be there," he tweeted.
"We need to find all parts soon so we can find all (our) guests to ease the pain of our families. That still is our priority," he said.