A mysterious third party has come forward with a technique that may help the FBI unlock an iPhone used by one of the San Bernardino terrorists, and a hearing scheduled for Tuesday on the agency’s battle with Apple over the phone has been cancelled.

The government asked the court to call off the hearing as it tests the technique. If it works, the government said, it would no longer require Apple’s help in bypassing the encryption on the iPhone used by Syed Rizwan Farook.

“We must first test this method to ensure that it doesn’t destroy the data on the phone, but we remain cautiously optimistic,” said Melanie Newman, a spokesperson for the Justice Department. “That is why we asked the court to give us some time to explore this option. If this solution works, it will allow us to search the phone and continue our investigation into the terrorist attack that killed 14 people and wounded 22 people.”

The government must provide an update to the court on April 5.

The development represents a remarkable twist in the high-profile case, which pitted the federal government against Apple and a who’s who of the technology and cyber security worlds in a battle over the future of encryption.

At the center of the case is a locked iPhone that the government argues might contain evidence in its investigation of the Dec. 2 terror attack. The court ordered Apple to write software to disable the security features on the phone so federal investigators could crack its password and gain access to the device.

Apple has countered that the government is asking Apple to build a new operating system that is simply too dangerous to create. The result would be a crippled, insecure product that would leave hundreds of millions of devices vulnerable to criminals and foreign agents.

“But we believe strongly that we have a responsibility to help you protect your data and protect your privacy,” Apple Chief Executive Tim Cook said on Monday, in remarks made at the company’s product launch. “We owe it to our customers and we owe it to our country. This is an issue that impacts all of us, and we will not shrink from this responsibility.”

As both sides prepared for a courtroom confrontation, a law enforcement source said, a third party appeared over the weekend to demonstrate a possible new approach to unlocking the phone. The government declined to identify the party or say whether this technique could be used to bypass encryption on other Apple devices.

The government said it sought Apple’s help only as a last resort, after having exhausted all known options. The Justice Department has repeatedly said that its request of Apple was drawn as narrowly as possible.

Meanwhile, the worldwide publicity generated by the case prompted others outside of the U.S. government to contact the government, offering suggestions — including this outside party demonstrating a new approach for unlocking Farook’s iPhone, according to court filings.

“Our top priority has always been gaining access into the phone used by the terrorist in San Bernardino,” said Newman. “With this goal in mind, the FBI has continued in its efforts to gain access to the phone without Apple’s assistance, even during a month-long period of litigation with the company.”

Apple attorneys said the company remains poised to fight the case in court, should that become necessary.

(Update: This story has been updated to note that Tuesday’s hearing has been canceled, not rescheduled.)