07/15/2013 10:29 am ET

'Downton Abbey' Casts Daisy Lewis As New Love Interest For Tom Branson (REPORT)


"Downton Abbey" has reportedly cast Daisy Lewis in a key role.

According to The Mirror, Lewis will play the live-in governess for the daughter of Tom Branson (Allen Leech) and the late Sybill Crawley (Jessica Brown Findlay).

"Daisy will become one of 'Downton's' most prominent characters. She wowed producers in her audition and they are delighted to have secured such a brilliant young actress," a source told The Mirror. Look for the two to start a secret affair.

Lewis' other credits include "Doctor Who" and "Downton Abbey" creator Julian Fellowes' "From Time to Time." Request for confirmation from Masterpiece was not immediately returned.

Lewis isn't the only new face popping up on "Downton Abbey." Gary Carr will portray the show's first black character, Jack Ross, a jazz singer. Other new cast additions include Tom Cullen, Nigel Harman, Dame Harriet Walter, Joanna David, Julian Ovenden and Dame Kiri Te Kanawa.

Additionally, Paul Giamatti will guest as Harold Levinson, Cora's (Elizabeth McGovern) brother in the "Downton Abbey" Season 4 finale with Shirley MacLaine, who returns as Martha Levinson.

"Downton Abbey" returns to PBS on Sunday, January 5, 2014 with Season 4.

"Downton Abbey"