A mystery investor has bought a stake of almost 5 per cent in JJB Sports.

A sale of just under 12 million shares was completed today JJB Sports confirmed but the identity of the buyer has yet to be revealed to the sports retailer.

The sale will re-ignite speculation that Sports Direct owner Mike Ashley is trying to build a stake in his rival to either launch a bid or be in a position to block a competitor’s bid.

JD Sports, Matalan and Tesco have all been touted as possible interested buyers for JJB, which completed a successful Company Voluntary Arrangement (CVA) last month.  

In the 16 weeks to May 17 JJB like for like sales fell 23.3 per cent as it continued to struggle with stock problems brought about due to lack of credit insurance and suppliers’ fear over the future of the business.