George Michael has spent $40 million on art this month.The 'Fastlove' singer snapped up works by controversial artist Damien Hirst - adding to his private collection which is now worth a reputed $160 million. A source told Britain's Daily Mirror newspaper: "George is hugely into his art. He made a lot of money from his 53-date tour last year and he thought this would be a good way to invest it."He's chosen pieces by Damien, photographer David LaChappelle and Tracey Emin. They wouldn't be to everyone's taste but they're hugely collectible and are certain to go up in value."The 43-year-old star will keep some of his prize collection in storage,while a selection of the works will go on display at his partner Kenny Goss Texas gallery. Earlier this month, the singer pleaded guilty to charges of driving while unfit through drugs dating last October.George embarked on his European '25 Live Stadium Tour 2007' last week.