A US hacker who gained notoriety for unlocking Apple's iPhone as a teenager has told BBC News that he has now hacked Sony's PlayStation 3 (PS3).
George Hotz said the hack, which could allow people to run pirated games or homemade software, took him five weeks.
He said he was still refining the technique but intended to post full details online soon.
The PS3 is the only games console that has not been hacked, despite being on the market for three years.
"It's supposed to be unhackable - but nothing is unhackable," Mr Hotz told BBC News.
"I can now do whatever I want with the system. It's like I've got an awesome new power - I'm just not sure how to wield it."
Sony said it was "investigating the report" and would "clarify the situation" when it had more information.
Mr Hotz said that he had begun the hack last summer when he had spent three weeks analysing the hardware.
After a long break, he spent a further two weeks cracking the console, which he described as a "very secure system".
He said that he was not yet ready to reveal the full details of the hack but said that it was "5% hardware and 95% software".
"You can use hardware to inject an insecurity and then you can build on that," he said.
He admitted that he had not managed to hack the whole system, including the protected memory, but had worked out ways to trick the console into doing what he wanted.
Mr Hotz said that he was continuing to work on the hack and, once finished, would publish details online in a similar way to his previous iPhone exploits.
In particular, he said, he would publish details of the console's "root key", a master code that once known would make it easier for others to decipher and hack other security features on the console.
He said his motivation was "curiosity" and "opening up the platform".
"To tell you the truth, I've never really played a PS3," he said. "I have one game, but I've never really played it."
Opening the system could allow people to install other operating systems on their console and play homemade games, he said.
In addition, he said, the hack would allow people to play older PS2 games on their consoles.
Recent versions of the PS3 do not have the ability to play PS2 games after Sony controversially removed a piece of hardware.
He admitted that it could also allow people to run pirated games.
"I'm not going to personally have anything to do with that," he told BBC News.
Gaming firms do not take the issue of game piracy and console modification lightly. Recently, Microsoft disconnected thousands of gamers from its online gaming service Xbox Live for modifying their consoles to play pirated games.
Mr Hotz said that the nature of his PS3 hack means that Sony may have difficulty patching the exploit.
"We are investigating the report and will clarify the situation once we have more information," said a Sony spokesman.
Mr Hotz rose to fame in 2007 at the age of 17 when he unlocked the iPhone, which could only be used on the AT&T network in the US at launch.
The hack allowed the popular handset to be used on any network.
He has since released various other hacks, allowing people to unlock later versions of the popular handset.