Deeside-based Iceland has axed Kerry Katona from its advertising campaigns.
The former member of Liverpool girl group Atomic Kitten and winner of ITV's reality programme 'I'm A Celebrity, Get Me Out Of Here' had featured in the company's advertisements for four years.
The food retailer said it was "impossible" for her to continue in the role, but said it would help her get support if she needed it.
Katona, from Warrington, had been facing allegations by a Sunday tabloid newspaper that she was taking Class A drugs prior to the sacking.
Iceland uses several celebrities to promote its stores including Loose Women presenter Coleen Nolan.
In January this year, Iceland completed the purchase of 51 Woolworths stores throughout the UK, following the collapse into administration of the 815-store group in November last year.