London Irish have confirmed the signing of Australia international James O'Connor until the end of the season.
The back, 23, has played 44 Tests for Australia and is set to make his debut this weekend against Northampton.
O'Connor has been allowed to move to England after the Australian Rugby Union terminated his contract following a string of off-field incidents.
"I thoroughly believe I can improve elements of my game by playing in the Premiership," said O'Connor.
The outside half, who can play anywhere along the back line, was told he would not be offered a contract with Australia for 2014 after a disciplinary investigation found he had "failed to uphold the behavioural and cultural standards expected within the team".
Earlier this month, he was escorted from Perth airport for drunken behaviour.
Australia are about to embark on a tour of Europe, with the Wallabies playing England at Twickenham on Saturday as they bid to complete a Grand Slam (beating England, Scotland, Ireland and Wales on the same tour) on a trip that also includes a Test against Italy.
"Having decided that I needed a change from both a personal and playing point of view, I spoke to clubs in Japan and France and concluded that the best way forward for my development was to move to England," he added.
"Given that I've left my support network back in Australia, London Irish offered me an environment that I felt comfortable with."
Exiles director of rugby Brian Smith said O'Connor was the "most significant signing in the club's history", adding: "His signing is the injection of class we need."
Smith said O'Connor deserves a second chance and believes he can still go on to make a huge impact on Australian rugby.
"James is a world-class player," Smith told BBC Radio Berkshire. "He is an asset for London Irish and the game over here.
"As an Australian, I see him as a player who can genuinely go on become the most capped Wallaby of all time and we hope to play a part in that."