The Qatari investment group involved in a raid on Sainsbury's shares has said it holds a stake of 17.4% in the British supermarket chain.
The move by Delta Two will increase pressure on Sainsbury's as the fund is thought to have links with tycoon Robert Tchenguiz, who has a 5% holding in the retailer and is pressing for it to unlock the value of its property assets.
The combination of the stakes owned by Mr Tchenguiz and Delta give the pair a bigger shareholding than the 18% owned by the Sainsbury family.
Delta did not reveal how much it paid for the stake, although it was reported that the shares changed hands at 575p, making the purchase worth £1.7bn (€2.48bn).
The developments come less than a fortnight after a £10.1bn (€14.78bn) private equity bid for Sainsbury's, led by CVC, collapsed after opposition from the Sainsbury family.
Mr Tchenguiz is understood to want the firm's freehold property assets to be listed separately from the supermarket business.
Nick Bubb, a retailing analyst at Pali International stockbrokers, said the key issue was whether the new investors could force a change of strategy from the Sainsbury's management prior to company results on May 16.
However, he added: "The presence of a big new shareholder won't in itself change the view of management on what they think is right for the business, just as the presence of Baugur as a major shareholder in Woolworths hasn't forced the management to break the group up."