He told City A.M. yesterday the firm is undergoing radical changes and the cash injection will help it realise its ambitions of turning around its fortunes.
He said: “The changes to the business are far-reaching and this doesn’t happen without investment.
“This is probably the last injection in the short-term but after that, who knows?
“The business is debt free and everything is being funded by Better Capital.”
The investment takes Better’s total expenditure on the business to around £23m.
The UK arm of the 87-year-old publisher filed for administration in February 2010, two weeks after the Pensions Regulator rejected a plan to plug the £125m hole in its savings fund.
Management at the company took a 35 per cent stake in the firm as part of the deal.
Reader’s Digest launched in the US in 1922. It made its name by taking on tobacco firms with a series of hard-hitting articles on lung cancer.