The Sunday Times reports that the group’s existing investors have provided the funding, which will be used for refurbishments across its c.50 remaining sites.
It comes after the burger chain shut 19 restaurants after entering in to a Company Voluntary Agreement (CVA) in 2018.
Byron posted a £55m pre-tax loss on sales of £88m in the year ending June 2017.
The company has since launched a turnaround plan which includes a “complete overhaul” of its design, service, supply chain and menu, including expanding its range of vegan and vegetarian options.
It also ran a buy one get one free offer on burgers for those signed up to its email marketing list in January this year.