[2] He spent six years from the age of 15 in Redemptorist monasteries in Australia and had begun training to be a Catholic priest in that order[2] when he returned to New Zealand and embarked on a lengthy career in film, television and media.
His early experimental short documentaries Ashes, The Town That Lost a Miracle, and All That We Need, led to an invitation to direct Tangata Whenua, a six-part television documentary series that presented the language, culture and politics of New Zealand's Maori people to a mainstream prime-time audience (in 1974) for the first time.
The series was made in collaboration with producer John O'Shea of Pacific Films and historian and writer Michael King.
Barclay wrote and directed The Neglected Miracle, a feature-length political documentary on the ownership of plant genetic resources.
After these documentary projects, Barclay collaborated with screenwriter Tama Poata on the feature film, Ngati (1987), produced by John O'Shea.