Businessman Mike Ashley's Sports Direct has upped its stake in department store chain Debenhams yet again.

A filing with the London Stock Exchange on Tuesday (22 August) revealed that Sports Direct's interest in Debenhams stood at 21%, up from 19%, continuing a series of increases dating back to 2014; the year its buying spree commenced via an initial 4.63% stake.

Sports Direct's current shareholding would net the company more than 10% of voting rights in Debenhams, and gives Ashley considerable clout in how the department store manages its business.

However, the owner of Newcastle United football club has described his stake raise as an "investment" and has ruled out a formal bid for Debenhams in the past.

The stake has been built up via combination of contracts for differences (CFDs) and share options. Debenhams shares rose on the news; up 1.45% or 0.59p to 41.30p at 11:45am BST.

Ashley's move is also in keeping with his practice of buying stakes in a plethora of retailers. Earlier this year, Sports Direct revealed a 27% stake in French Connection. Just last month, Sports Direct also acquired a 26% stake in Game Digital.

In the past, Ashley has built up stakes in retailers House of Fraser and Findel, and previously owned a stake in JD Sports, a direct competitor of Sports Direct.