'Brothers and Sisters' star Getty to shack up with Sienna Miller

Jul 18, 2008, 10:00 GMT

05/31/2008 - Anna Getty and Balthazar Getty - 7th Annual Chrysalis Butterfly Ball - Private Brentwood Residence - Brentwood, CA USA © Chris Hatcher / PR Photos

Sienna Miller is set to move in with Balthazar Getty.

The 26-year-old actress is reportedly planning to set up home with the oil heir just weeks after splitting from actor Rhys Ifans.

The Los Angeles mansion where Balthazar lives is now empty after his wife and four children moved out following news of his alleged affair.

Balthazar, 33, is believed to have suggested the move after the pair's recently romantic break in Italy.

A source told Britain's Daily Mirror newspaper: "Before they went on holiday, Sienna was staying over at Balthazar's place all the time. Sienna told a few friends that Balthazar had made some noises about moving in. Then during the holiday their feelings for each other got stronger.

"She doesn't want to move into the family home because of all the history with his ex-wife, so they are planning to buy somewhere new. But her friends are worried she is rushing into it."

Sienna was first spotted in public with Balthazar at the end of June.

The couple were introduced earlier this year by Sienna's 'Edge of Love' co-star Matthew Rhys - who stars alongside Balthazar in hit US TV show 'Brothers and Sisters'.

Following the news of the affair, Balthazar's wife Rosetta fled the US taking their four children - Cassius, eight, Grace, seven, Violet, four, and June, 10 months - with her.

Meanwhile, Sienna was back in the UK yesterday (17.07.08). Her ex-lover Rhys Ifans is said to be desperate to retrieve his possessions from the London house they used to share - after Sienna changed the locks before her holiday with Balthazar.

A source said: "Rhys left clothes, books and things at her place but had to wait until she got back to get them. The last thing he wanted to do is see Sienna. Those pictures of her on holiday with Balthazar really hurt him."