Model-turned-actress Cara Delevingne has been given a makeunder to portray a homeless drug addict in a hard-hitting new music video.

The Suicide Squad star was recruited by The Spencer Lee Band to feature in the promo for River Water, in which Cara plays a down-and-out young woman begging for change on the streets.

The song and its message is particularly personal for frontman Spencer Lee, as he drew inspiration for the track from his own experience as a homeless musician in Los Angeles, before he was discovered by Justin Bieber's manager Scooter Braun, and signed to Republic Records last year (17).

"Sometimes, folks walk down the street and see a 'homeless guy or girl' and what I want people to realise is - that's a person - just like you and me - struggling to just get by," he says.

"Cara came along and completely nailed the role in the video," he adds. "It was made to show that someone can be fine one day and homeless the next. I put it out in hopes it will raise awareness and compassion (about homelessness)."

Cara's appearance in the River Water promo is a far cry from her recently-released ad campaign for luxury designer Burberry, in which the beauty also shows off her vocals to promote the top brand's Her Eau de Parfum.

In a short video accompanying the print campaign, the 26 year old literally sings the praises of her London hometown as she rides atop a double decker bus and gazes at the city's famous landmarks.

"Maybe it's because I'm a Londoner," she sings, "that I love London so."

It's not the first time the Brit has displayed her vocal talents - she released her first music venture last year (17) with the track I Feel Everything, from the soundtrack to her film Valerian & the City of a Thousand Planets.