Legendary British music producer Sir George Martin, best known for his work with The Beatles  and often referred to as "the fifth Beatle" has died, aged 90, according to a message on social media from former Beatle drummer Ringo Starr.

A Universal spokesperson confirmed his death to The Hollywood Reporter though details are not yet clear.

The composer, arranger and musician is famed for his work with The Beatles in the 1960s and '70s, and was considered one of the greatest record producers of all time, with 30 number one singles in the UK and 23 in the US, throughout his career.

It's his work with The Beatles, though, that he will perhaps be best remembered. Martin signed the Fab Four in 1962 and went on to produce almost their entire catalogue.

Ringo Starr tweeted on Wednesday afternoon "God bless George Martin", followed by another tweet with a photo of the band and Martin in their heyday.

After studying music, Martin worked at the BBC in the classical music department, before moving to record company EMI, where he produced comedy records ith the likes of Peter Sellers and Spike Milligan as well as jazz and lounge records.

Martin worked with other big names throughout his career, including Gerry & The Pacemakers, Elton John, Cheap Trick, Celine Dion, Jeff Beck and Kenny Rogers, winning seven Grammy Awards and two Brit Awards.

He also composed music for film and television, including Shirley Bassey's Goldfinger in 1964 and Paul McCartney and Wings' Live And Let Die in 1973.

(Sydney Morning Herald)