Frank Wilson, who sang the sought-after Northern Soul single Do I Love You (Indeed I Do) and produced a string of Motown hits, has died aged 71.
The Houston native wrote and produced for artists such as Marvin Gaye, The Supremes and The Temptations but only released one single as a vocalist.
Just two or three copies survived - one of which sold at auction for more than £25,000 in 2009.
Wilson had fought a long battle with prostate cancer but died on Thursday.
Just 250 demo copies of Do I Love You (Indeed I Do) were pressed on 7-inch vinyl, but Wilson decided he would rather focus on producing, so they were trashed.
A rare remaining copy which changed hands in 2009 is the most expensive record ever sold at auction. A prized item among collectors, the song is regarded as a Northern Soul classic in the UK.
"It's always seen as the epitome of the Northern Soul style," said promoter Ady Croasdell who runs the 6T's Northern Soul All-Nighter at London's 100 Club.
"It probably is the most iconic record of the lot, because it does have all the qualities that a classic Northern Soul record should have."
Croasdell revealed news of Wilson's death on the Soul Source website, after being emailed by mutual friend, Los Angeles producer HB Barnum.
Crossdell told the BBC: "He was a much-loved man with a friendly disposition who was delighted and humbled by the Northern soul scene's admiration of his singing."
Wilson was more widely known for his work as a producer and joined Motown in 1965, when the record label set up an office in Los Angeles where he lived.
That year he co-wrote Patrice Holloway track Stevie, the first single to be released by Motown's west coast operation.
He then re-located to their studios in Detroit, where he worked with artists such as Brenda Holloway, The Four Tops and Eddie Kendricks.
He co-wrote tracks including Love Child and Stoned Love by the Supremes, All I Need by The Temptations, Chained by Marvin Gaye and Whole Lot of Shakin' in My Heart by Smokey Robinson & the Miracles.
He was born Frank Edward Wilson on 5 December 1940 in Houston to James Wilson and Samantha Gibbs, but moved to Los Angeles with his family while he was a teenager.
Wilson left Motown in 1976 and became a born again Christian. After being ordained as a minister, he wrote books and gave speaking tours around the US with his wife Bunny Wilson.
He was also involved in producing gospel music and founded the New Dawn Christian Village in Los Angeles.
His books include The Master Degree - Majoring in Your Marriage; and Unmasking the Lone Ranger. He also appeared on TV programmes such as The Oprah Winfrey Show.