Nicole Richie has moved next door to Cameron Diaz.

The 'Candidly Nicole' star and husband Joel Madden - who have seven-year-old daughter Harlow and five-year-old son Sparrow together - recently relocated into the same Beverly Hills enclave as his twin brother Benji and his 'Sex Tape' actress wife.

A source has told Us Weekly magazine the couple bought a $6.7 million four-bedroom home which ''is just a few doors down from Cameron's'' and moved in earlier this month.

Both couples are extremely close and the 33-year-old reality TV star previously admitted she was responsible for setting her brother-in-law up with Cameron just seven months before they tied the knot in January.

She said: ''Yes. I'm going to take responsibility for everything! I approve of anything that's going to make Benji happy.

''I am a devoted sister-in-law. I'm happy for anyone who is happy, and I want everyone to be surrounded with love.''

Meanwhile, Cameron has also become a devoted aunt to Sparrow and Harlow.

The source said: ''She's more determined to have a baby, seeing how wonderful Nicole's family life is. She's inspired by Nicole on many levels.''