Known to many people as the "Fifth Beatle," Neil Aspinall, a longtime friend and runner of the Apple Corps music empire for the Beatles, passed away in a New York hospital. He was 66.

Once the Beatles' road manager and assistant, Aspinall was receiving treatment for lung cancer at Memorial Sloan-Kettering Cancer Center when he died. Of all the people to have ever be in the Beatles' entourage, he had the most durable relationship with the group.

His death was announced in a statement released by Paul McCartney and Ringo Starr, the widows of John Lennon and George Harrison, and the band's Apple Corps Ltd. company.

"The Beatles and the entire Apple Corps family, both past and present, wish to extend their greatest sympathy to the family of Neil Aspinall. As a loyal friend, confidant and chief executive, Neil's trusting stewardship and guidance has left a far-reaching legacy for generations to come. All his friends and loved ones will greatly miss him but will always retain the fondest memories of a great man," the statement wrote.

Aspinall reportedly fell ill to lung cancer two months ago when according to the British media McCartney flew to New York to visit him on his deathbed. A family friend told the Daily Mail of McCartney's recent visit. "I understand that Paul saw him in hospital in New York," the friend said. "Paul will be devastated if he doesn't beat this. They have been mates ever since they were schoolboys in Liverpool."

George Harrison also passed away of lung cancer in 2001 while McCartney's first wife, Linda, died of breast cancer in 1998.

Aspinall is survived by his wife Suzy and five children.

"I've known Neil many years and he was a good friend. We were blessed to have him in our lives and he will be missed," Starr said in a separate statement.

A school friend of Sir Paul McCartney and George Harrison, Aspinall's history with the British rock group goes far back, to the early beginning of the band when he used to drive the so-called Fab Four to gigs in his van. He later became their personal assistant, and in 1968 was given a management role at Apple Records — The Beatles' own record label.

Aspinall also played background instruments on tracks including "Magical Mystery Tour," "Within You Without You" and "Being for the Benefit of Mr Kite."

After serving as chief executive of Apple Corps for four decades, Aspinall stepped down in April last year. Before retiring however, Aspinall had begun work on a licensing agreement to put the Beatles catalogue on iTunes, amid reports of disagreements with members of Apple music over a re-release program.