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Natalie Portman is romancing the big brother of Miley Cyrus' Australian boyfriend, according to U.S. tabloid reports.

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Portman met "Star Trek" actor Chris Hemsworth after they were cast together in forthcoming movie "Thor."

Shooting isn't scheduled to begin until January, but the pair is reportedly dating already.

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A source tells Star magazine, "Sparks have been flying since their first meeting. He seems to have a crush on her, and she clearly loves the attention."

Cyrus found love with Chris' sibling Liam Hemsworth after the pair shot new movie "The Last Song" together.

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Portman has been single since splitting from folk rocker Devendra Banhart last year.