The Sunday Times reports that Owen Carey, from Crowborough, East Sussex, suffered a fatal allergic reaction hours after ordering a grilled chicken burger at Byron in north Greenwich, London in April 2017.
He had multiple allergies, including dairy, and was celebrating his 18th birthday.
The Carey family’s law firm, Leigh Day, wants to establish whether the chicken contained buttermilk, which was not disclosed on the menu.
The inquest resumes at Southwark coroner’s court this week.
Byron CEO Simon Wilkinson says in a statement: “Byron would like to extend our deepest condolences to Owen’s family. We always take food allergies extremely seriously and have a comprehensive set of measures in place.”
The hospitality industry is facing greater scrutiny over its handling of allergens following several high-profile cases. In 2016 restaurant owner Mohammed Zaman was jailed for six years for manslaughter after the death of a customer with a peanut allergy in what was thought to be the first case of its kind.
Pret a Manger now lists all ingredients on its packaging after the death of 15-year-old Natasha Ednan-Laperouse, who suffered an allergic reaction to eating a sandwich bought at the chain in 2016.
Last week ‘Natasha’s Law’ was put before parliament, which will ensure foods such as packaged sandwiches and salads prepared on-site will have to display a full list of ingredients.
The rules will be implemented in England in 2021, but similar arrangements are expected to follow in other parts of the UK.