Chris O'Dowd is to head the cast of a new BBC "mockumentary" series which will reunite the stars of hit movies such as This Is Spinal Tap and Best In Show.
Family Tree, which is to be screened by BBC2 next year, will also feature actress and ventriloquist Nina Conti.
The film will once more bring together Spinal Tap stars Michael McKean and Christopher Guest, who co-wrote and created the series. Other names who have figured in their films, such as Fred Willard and Don Lake, are also in the cast of the eight-part series.
It follows character Tom Chadwick, played by O'Dowd, who tries to unravel his family history after inheriting a box of belongings from a relative.
Guest - who created and scripted the show with British actor and writer Jim Piddock - is noted for his documentary-style, semi-improvised films.
Family Tree, a co-production with US firm HBO, is currently being made in the UK and it will be screened in the spring.
Irish star O'Dowd said: "I'm terribly excited and monumentally under-qualified to work on an improvised show with Chris Guest."
Guest joked: "Chris O'Dowd has been on my radar ever since he was a child actor in Wales."
BBC2 controller Janice Hadlow said: "I am delighted to welcome Christopher Guest to BBC television. It will be his first television series for British audiences and one I am proud to have here on the BBC."