Brian May surprised a West End audience by making an appearance as Santa Claus at the end of a show.

The Queen guitarist made the special trip to the London theatre to surprise the cast of the musical We Will Rock You.

The show features the music of Brian's legendary rock band, and his entrance at the end of the Boxing Day performance delighted the stars of the show.

"At first the cast were unsure who was underneath the fake beard and costume," a source told British newspaper The Sun.

"Then they spotted Brian's curly [hair] and twigged. No one suspected it was the guitar legend."

Brian is no stranger to making guest appearances.

He joined rock band The Darkness on stage during the encore of the final date of their comeback tour last month.

The 64-year-old British musician joined the band for the hit tracks Bareback and I Believe in a Thing Called Love, plus a cover of Queen's own Tie Your Mother Down.

The musicians gained a rapturous applause for Brian's entrance.