Frank Cox was the identical twin of Fred Cox who, as the Cox Twins, were one of British variety's most enduring acts. Stalwarts of the RAF gang shows during the Second World War, they played four instruments, sang, tap-danced and performed acrobatics.

After the war and until their retirement in 2000 they were regulars at the London Palladium, notably supporting Johnny Ray, starred in summer seasons and pantomimes and made several films, including the 1972 version of Alice in Wonderland with Peter Sellers, in which they appeared as Tweedledum and Tweedledee.

The twins had irresistible, ebullient personalities. Sporting huge black frizzy hairstyles, they wore brightly coloured garish suits (complete with red or yellow socks) and were liable to burst into song at the drop of a hat. They were virtually impossible to tell apart and in conversation one twin would start a sentence while the other would finish it. In the 1960s they complicated matters further by getting married on the same day to the variety artistes Estelle and Pauline Miles, who were also identical twins.

They all lived together in the same house in North London, where, as the comedian Jack Seaton recalled, “if you lunched with the four of them you hadn't a clue who was who”.

Francis Thomas Cox was born in Cardiff in 1920 and, at the age of 12, he and his brother Fred joined Steffani's Silver Songsters, a touring boys choir — which included a young Norman Vaughan — as speciality clog dancers. The Songsters toured music halls across the country, often supporting leading variety artistes and, after leaving the choir, the twins joined a show with the singer Dorothy Squires.

At the outbreak of war they joined the RAF and were stationed at Padgate, Winston Churchill having stated that RAF personnel who were twins should stay together. They appeared in troop shows with success, although their long hair caused considerable comment, not least from one RSM who fumed: “These boys will ruin the RAF.”

They were quickly transferred to the RAF gang shows, under the auspices of Ralph Reader, who was to become a lifelong friend. The twins' involvement with the gang shows spanned 50 years, much of the time spent as welfare and entertainment officers. In wartime they toured Britain, Europe, the Gulf and the Far East in company with up-and-coming stars such as Peter Sellers, Tony Hancock and Dick Emery, often in hazardous conditions. On a visit to Tangmere Aerodrome, in Sussex, they had barely left their lorry when it was machinegunned by a lone Messerschmitt 109 fighter and in Normandy they were in a bunker with Ralph Reader when Stuka bombers started strafing them from low level. “If we ever get through this, boys, you'll never want for work,” said Reader. “When we get back home I'll look after you.”

After the war Frank and Fred were key figures in the RAF gang show reunions and recently they created a book of remembrance dedicated to the shows at St Clement Danes, the RAF church in London.

In postwar variety they were never out of work. They made several films including Up Jumped a Swagman (1965) with Frank Ifield, and Funny Bones (1995) with Lee Evans and Jerry Lewis. Their numerous television appearance included Barrymore and The Story of Light Entertainment (2006) with Stephen Fry and Simon Cowell.

After Frank's wife Estelle died in 1984 they appeared on stage as the Cox Twins and Pauline. In 2000 they were given a Lifetime Achievement Award from the British Music Hall Society.

He is survived by his brother.

Frank Cox, variety artiste, was born on December 4, 1920. He died on November 10, 2007, aged 86