A former owner of Boots the Chemist is weighing a $6bn (£4.7bn) takeover bid for the US-based parent company of Holland & Barrett, the high street health foods chain.
Sky News understands that KKR is among a small number of potential bidders for NBTY - a vitamins and nutritional supplements manufacturer previously known as Nature's Bounty.
Final bids for NBTY are due to be tabled in May, according to people close to the process, and it is possible that KKR will not be among the parties which submit a revised offer.
Holland & Barrett trades from close to 1,400 stores in 16 countries.
Approximately half of its wholly owned shops are in the UK, where it is one of the most familiar names on the high street.
NBTY's owner, Carlyle, has been exploring a sale of the business for the last few months, and has invited bidders to register their interest both for the whole company and its constituent parts.
Carlyle is said to have a strong preference for selling the entirety of NBTY in one transaction because of substantial tax liabilities that could be triggered by a break-up.
Bain Capital, another big private equity group, has also tabled a bid, which represents a bet on the continued growth of international consumer demand for health foods and nutritional supplements.
Last month, Bloomberg News reported that Carlyle was also considering a New York listing for NBTY.
Holland & Barrett is based in Nuneaton, Warwickshire, where it employs about 350 people.
Its parent company was bought by Carlyle in 2010 in a deal worth $3.8bn and has a global workforce of 11,000.
KKR and Carlyle declined to comment.