Alistair Becket is the secondary antagonist of Joe Camp's 1980 fantasy film Oh! Heavenly Dog.
He was portrayed by the late John Stride.
Jackie interviews Quimby Charles at Scotland Yard, who insists on access to her research, which he hopes will clear his name as a suspect. Soon, Jackie visits the Needham Gallery, and leaves Browning in her parked car. There, she meets Montanero, an artist whose work Patricia often used in her interior design work, and Jackie invites him to her flat for dinner. Jackie is introduced to Becket, who shows great interest in her book. Browning searches the gallery, and soon sees Jackie talking to Bart, the killer. At the sight of the dog on Jackie's lap, Bart becomes leery and leaves. Browning wiggles free from Jackie's grasp and follows Bart.
Later, Jackie asks for Patricia's client list, but her building manager refuses. Later still, Jackie interviews Becket, and asks his help to gain access to Patricia's flat. He then summons Bart, his assistant. While the men talk with Jackie, a painting of the Swiss Alps hanging in Becket's office reminds Browning that Patricia vacationed there, and he suspects a connection. Later in Patricia's flat, Browning sees Bart remove evidence. Suddenly, Mr. Higgins appears, and temporarily switches the dog back to his human form to warn him that a mistake was made. His dog body will expire sooner than expected, and he will have to leave before he solves his murder. Benjamin protests, and says he will not leave before the crime is solved.
Meanwhile, Becket alerts Jackie that her dog was found by building security, and is being held in Bart's office. Browning sees a calendar entry on Bart's desk, noting Becket's birthday and a street address. When Jackie notices the entry, she wishes Becket a happy birthday. However, he says that his birthday is 3 March not October, and casually invites her to lunch. Soon, Browning investigates the address, which is a post office, and decides to search postal box #33, based on the numerals of Becket's birthday. Browning grabs a letter out of the box and escapes. At Jackie's apartment, Browning rips open the envelope to find Patricia's pendant with the word "ALP"stamped on the back. Upon realizing the letters stand for "Alistair loves Patricia,"Browning searches Jackie's police photographs and notices that Patricia was no longer wearing the pendent. He deduces that Patricia became a political liability for the married Becket once he intended to run for prime minister, and she became engaged to his rival, Quimby. Therefore, Becket and Bart schemed to get rid of her. Browning grabs the pendent in his mouth and heads to Jackie's lunch. However, Bart chases him until Browning runs into an alley. There, Browning transforms into human form, and Mr. Higgins appears, saying Benjamin's time on Earth is over. Bart is shaken to see Benjamin, and leaves after the dog is nowhere to be found.
Meanwhile, Benjamin will not cooperate with Higgins, and shows up at the restaurant as Browning with the pendant in his mouth. Becket grabs the pendant away from Jackie, and accuses her of derailing his plan to become prime minister. Browning turns on Jackie's tape recorder just as Becket confesses his love for Patricia. When Jackie accuses Becket of murder, Bart appears and confesses to the crime. After twelve years preparing Becket to become prime minister, Bart did not want Patricia to ruin their political ambitions. Bart is eventually arrested when he tries to shoot Browning but hits Jackie instead as she shields the dog from harm.