Family Tree, the new BBC Two/HBO comedy series starring Chris O'Dowd and co-written by This Is Spinal Tap and Best in Show's Christopher Guest, is in production in the UK.

The single-camera, documentary-style comedy follows Tom Chadwick (O'Dowd), whose loss of job and girlfriend coincides with his inheritance of a mysterious box which prompts him to investigate his family lineage.

Co-created by Guest and Jim Piddock (Best in Show, Independence Day), Family Tree will continue filming in the UK and Los Angeles until early 2013, and will premiere on BBC Two and HBO next spring.

The cast also includes Nina Conti as O'Dowd's screen sister Bea, Tom Bennett as his best friend Pete, Ed Begley Jr, Maria Blasucci, Matt Griesser, Don Lake, Michael McKean, Lisa Palfrey, Amy Seimetz, Fred Willard and creators Guest and Piddock.

O'Dowd said of the series: "I'm terribly excited and monumentally under-qualified to work on an improvised show with Chris Guest. I call him Chris ‘coz we are friends. He calls me George. I don't know why."

Guest added: "I am very lucky to be working with an incredibly talented cast. Chris O'Dowd has been on my radar ever since he was a child actor in Wales."