SPORTS Direct has again upped its stake in department store chain Debenhams.

The retailer, led by Newcastle United owner Mike Ashley, has raised its interest in the high street staple from 19 per cent to 21 per cent, the latest in a series of increases.

Mr Ashley's intentions in boosting his firm's holding have been the subject of speculation, although few have tipped the billionaire to attempt a full-blown takeover.

Sports Direct has in the past said it simply wants to be a "supportive stakeholder" in Debenhams, and to create value in the interests of shareholders of both firms.

The retailer began building its stake in Debenhams in 2014 and last made a raid on its shares in June.

Sports Direct has built its position through a combination of share options and contracts for differences.

Mr Ashley has a history of building up positions in rival retailers, having previously bought stakes in JD Sports and privately-owned House of Fraser.

Sports Direct also snapped up a 27 per cent stake in French Connection earlier this year, raising fresh questions over the chain's future.