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In an interview with BBC Newsnight, Chanel Williams, 35, says James had kept the struggle - including being hospitalised because of the drug - a secret from the family "to protect them".

Chanel is now hoping to continue that legacy by campaigning to encourage people to talk openly about substance abuse.

Since making the announcement, they've been working with substance abuse charity Adferiad to raise awareness and tackle stigma around the drug, something Chanel says is an "important step" in those facing addiction.

Chanel said it had been difficult to share the information about how James had passed away but that the family "talked about what we can do".

You can see the full interview with The Vivienne's sister Chanel on BBC Newsnight at 10:30 on BBC Two and BBC iPlayer.