Channel 4 has said its Moors murders drama is more about campaigner Lord Longford than the killings.

Penal reform campaigner Lord Longford called for murderer Myra Hindley to be released and allowed to rehabilitate.

"We don't really go into the hideousness of the crimes," said Channel 4's Kevin Lygo. "The drama is about Longford and his Catholic-induced obsession with forgiveness.

"It follows his story and asks whether forgiveness is appropriate in this case. The film has extraordinary performances."

Lord Longford is played by Jim Broadbent, while Oscar-nominated Samantha Morton plays Hindley. Andy Serkis (King Kong, Lord of the Rings) plays Hindley's lover Ian Brady.