The Pure South Handpicked 55 Day Aged Beef won best grass-fed steak and the best ribeye steak at the World Steak Challenge in London last week.

The beef, which was selected from Alliance Group's Pukeuri plant in Oamaru and aged in a vacuum bag for up to 55 days, was one of six winners in the global contest.

Shane Kingston, general manager sales and marketing at Alliance Group, said the awards recognised the "dedication and hard work our farmers put in day in, day out to raise the best grass-fed red meat in the world".

Kingston said the ribeye steak, which costs around $25 for 500g, has "unprecedented" levels of tenderness and a "robust, zesty, buttery, and creamy flavour that gives it a deeply satisfying savoury presence".