John Line was born in Birmingham, hailing from a family with a strong medical background. His was educated at Sibford and Bromgrove, and then at the Handsworth Grammar School, before undertaking National Service in the Royal Medical Corps and gaining a degree in Psychology.

Taking up acting, he often took on medical roles, such as Andrew Stone in Emergency Ward 10, Dr Robertson in General Hospital, Dr Parkin in Out Of Bounds, Dr Ryan in Crossroads. Other appearances included Wings, Howard's Way, The Onedin Line, Secret Army and Brookside. He retired in 2009 after playing God in the film My Last Five Girlfriends.

His first brush with Doctor Who came with an appearance in the David Whittaker penned stage play The Curse Of The Daleks as Lavider - a role he resurrected for Big Finish in 2008. He then went on to appear in the show itself as Martin in Colony In Space.

He married Jill Rowland in 1957, and is survived by her and his three sons, Matthew, Kit and Jason.