Concerns are mounting for renowned Bristol DJ Derek Morris, who has not been seen for three weeks.

The disc jockey's family are said to have reported the 73 year old missing on 23 June to Avon and Somerset Police, who are now investigating his whereabouts.

Morris's niece has told BBC News that her uncle's disappearance is "completely out of character", adding: "I've left numerous messages for him and he hasn't got back – if he goes away he always lets me know.

"His friends have been in touch to say he hasn't been in contact. We're all extremely worried."

A spokesperson for the police also told The Independent: "We were made aware last night by family members of Derek Morris's disappearance. We are actively looking for him.

"He is described as a white male, average height and slim build with grey hair. He also wears glasses."

Bristol's first elected mayor, George Ferguson, has expressed his concern and promised to contribute to the search, tweeting:

Who is DJ Derek?

Credited as being the UK's oldest DJ, Morris has enjoyed an unmatched and successful career in the music industry – but his humble beginnings could not be more far removed from the icon he eventually became.

Morris had been working in the accounts department of confectionary company Cadbury's when in the late 1970s he took a complete U-turn and launched a career in music.

The DJ gradually rose through the ranks, regularly playing clubs in the Bristol area and spinning tracks within the reggae, ska, dancehall, soul, lover's rock and rocksteady genres, attracting a huge following within the Jamaican community and wider Bristol area.

It did not go unnoticed that Morris appeared to be the most unlikely reggae DJ – a nerdy-looking white man with a background in accounting.

During an interview with Exposé, the musician admitted that he has been called a "white n****r" on a previous occasion due to his love of music deeply rooted in the African and West Indian cultures.

Watch DJ Derek perform his last ever outdoor gig:

However, laughing in the face of racism, Morris's career continued to soar, and he was consistently supported by fellow Bristolians Massive Attack.

Morris was able to set himself apart from the competition by MCing in convincing Jamaican patois during his DJ sets.

Despite the difference in generation, chart-topper Dizzee Rascal honoured the DJ's legendary status by giving him a cameo appearance in the music video for his 2009 single, Dirtee Disco.

Over the last four decades, Morris has toured extensively and has played at a range of festivals around the world, including regular slots at Glastonbury and The Big Chill in the UK. He has also released a compilation album of his favourite tracks.

Watch DJ Derek perform at Bestival in 2010:

Much to the disappointment of longtime fans, Morris announced that he would be retiring from music in 2013 at the age of 71.

Reflecting on his lengthy career, Morris told We Love Cool Beans: "As a younger man spending most of [my] time on the dole to then be invited to play the music that I love is extremely humbling.

"Back then a lot of black people thought that white people had been using black music, they've been conscious of the fact that I've been promoting black music."

Despite his retirement, the Bristol Post has reported that Morris is scheduled to play a set at the Arcadia concert in the city's Queen Square in September 2015.

Anyone with information about Morris's whereabouts or disappearance have been asked to contact the police on 101.