After graduating from drama school Elphick was offered roles primarily as menacing heavies. He made his debut in
Fraulein Doktor (an Italian-made
First World War film circa 1968). He went on to play the Captain in
Tony Richardson's version of
Hamlet (1969); landed parts in cult films such as
The First Great Train Robbery and
The Elephant Man and appeared in
Lindsay Anderson's allegorical
O Lucky Man! (1973). He was also seen as
Phil Daniels' father in the cult film
Quadrophenia (1979), as Pasha in
Gorky Park (1983) and as the poacher, Jake, in
Withnail & I (1987). In 1984 he played the lead, Fisher, a British detective recalling under hypnosis a dystopian, crumbling Europe and his hunt for a serial killer, in Lars von Trier's
Palme D'Or nominated debut film,
The Element of Crime. On stage, Elphick played Marcellus and the Player King in Tony Richardson's stage version of
Hamlet at the
Roundhouse Theatre and on Broadway and he later played Claudius to
Jonathan Pryce's Hamlet at the
Royal Court Theatre, directed by
Richard Eyre. In 1981 he appeared in the
Ray Davies/
Barrie Keeffe musical
Chorus Girls at the
Theatre Royal, Stratford East and he was also seen in
The Changing Room, directed by Lindsay Anderson, at the Royal Court Theatre. His last West End stage appearance was in 1997 as Doolittle in
Pygmalion directed by
Ray Cooney at the
Albery Theatre. However, it was for his television roles that Elphick became best known. He briefly appeared in
Coronation Street (1974) as Douglas Wormold, son of the landlord Edward, who for many years owned most of the properties in the road. Douglas unsuccessfully tried to buy the newsagent shop The Kabin from
Len Fairclough. He played three characters in the popular
Granada Television series
Crown Court: in 1973 as a defendant; in 1975 as a witness (Frank Hollins, private secretary to a female
soprano in the episode
Songbirds out of Tune); and from 1975 to 1983 as the barrister Neville Griffiths Q.C. He played one of the main roles in the film
Black Island in 1978 for the Children's Film Foundation, played a villain in
The Sweeney episode "One of Your Own" (1978) and played a policeman in
The Professionals episode "Backtrack" (1979) and had a minor role in
Hazell (1979), and appeared in the
Dennis Potter play
Blue Remembered Hills (1979). Elphick took the title role in
Jack Pulman's six part comedy-drama
Private Schulz (1981). Here he played alongside
Ian Richardson the German forger Gerhard Schulz, who is conscripted into SS Counter Espionage during the
Second World War to destroy the British economy by flooding it with forged money. He appeared as the Irish labourer Magowan during the first series of
Auf Wiedersehen, Pet (1983) and starred as Sidney Mundy in the ITV sitcom
Pull the Other One (1984), before playing Sam Tyler in four series of
Three Up, Two Down (1985–89). In 1986 Elphick landed his biggest television success,
Boon (1986–92, 1995). He played Ken Boon, a retired fireman who opened a motorbike despatch business and later became a private investigator. Boon was very successful and ran for seven series, attracting audiences of 11 million at its peak. There was also a one-off episode screened in 1995, two years after it had been made. During breaks from Boon, Elphick continued to act in film with cameo roles in
The Krays (1990) and
Let Him Have It (1991), and in 1991 he played Des King in ''
Buddy's Song, starring Chesney Hawkes and Roger Daltrey. For Independent Television company TSW, he took a rare TV presenting role, alongside Don Henderson from The XYY Man, in the food programme The Absolute Beginner's Guide to Cookery''. In 1993 Elphick took the role of a former
Fleet Street journalist running a
Darlington news agency in
Harry (1993, 1995). He played the alcoholic and ruthless Harry Salter, who frequently used exploitation and underhand tactics to get a story. This series however was less successful and it was soon cancelled. Elphick went on to play
Billy Bones in
Ken Russell's televised version of
Treasure Island (1995) and Barkis in
David Copperfield (1999). In 2001 he joined the cast of
EastEnders, where he played
Harry Slater, a romantic interest for
Peggy Mitchell (
Barbara Windsor). The plotline indicated that Slater had sexually abused his niece,
Kat Slater (
Jessie Wallace), at the age of 13 and her "sister"
Zoe (
Michelle Ryan) was the daughter born to her when she became pregnant by him. Elphick's heavy drinking began to affect his performances, so the character promptly left the series and was killed off off-screen. ==Personal life==