His agent Barrie Marshall said the Grammy Award-winning artist was "simply unique" and "it will be impossible to fill the space he leaves in our hearts".

He died at his home in Colorado in the US on Monday, local time.

Cocker had a career spanning 50 years, and was perhaps best known for hits You Are So Beautiful and Up Where We Belong, and a cover of The Beatles' With A Little Help from My Friends, which he performed at Woodstock in 1969. That song went on to become the theme song for the television show The Wonder Years.

Ringo Starr was among the first to pay tribute to the musician on social media, tweeting: "Goodbye and God bless to Joe Cocker from one of his friends peace and love."

The raspy-voiced singer was "without the doubt the greatest rock/soul singer ever to come out of Britain," Marshall said in a statement.

Sony Music released a statement confirming the singer's death.

"John Robert Cocker, known to family, friends, his community and fans around the world as Joe Cocker, passed away on December 22, 2014 after a hard fought battle with small cell lung cancer. Mr. Cocker was 70 years old," the statement said.

"Joe Cocker was born 5/20/1944 in Sheffield, England where he lived until his early 20s. In 2007 he was awarded the OBE by the Queen of England.

"His international success as a blues/rock singer began in 1964 and continues till this day. Joe created nearly 40 albums and toured extensively around the globe."

Cocker was born in Sheffield, England, where he worked as a gas fitter while pursuing a singing career, covering Motown songs in pubs in northern England in the 1960s.

He became known as a white soul singer and for his unique stage presence, twisting his body and face into contortions as he sang with his signature husky delivery.

A recording and touring artist in the 1970s, Cocker struggled with alcohol and drug abuse. He had a big hit in 1974 with You Are So Beautiful, co-written with Billy Preston.

His career revived in 1982 when he recorded a duet with Jennifer Warnes, Up Where We Belong. The song featured on the sountrack of the film An Officer and a Gentleman, and went on to win a Grammy and an Oscar.

He recorded 23 studio albums, including Fire It Up. He released his last album in 2012.

Cocker was awarded the OBE for services to the music industry in 2007.

He toured extensively in Australia, most recently in 2011.

However, his most controversial visit was in 1972, when he and six members of his entourage were arrested for marijuana possession. Cocker was asleep when police raided his hotel room after a concert in Adelaide.

Cocker and his entourage were bailed for $1000 each by his promoter. The singer pleaded guilty and continued the tour in Melbourne, where at a concert five days later he yelled out: "In five years marijuana will be legalised in Australia, and the same cat who is trying to throw us out now will be smoking it himself".

The next day, immigration minister Jim Forbes gave Cocker four hours to leave the country. 

Cocker is survived by his wife Pam, brother Victor, step-daughter Zoey Schroeder and two grandchildren, Eva and Simon Schroeder.

With Reuters