Sports Direct boss Mike Ashley has lost a second key ally in the space of a week after the retailer’s company secretary stepped down.

Cameron Olsen, who has worked for Ashley for 15 years, quit on Monday, according to documents filed at Companies House.

Olsen’s resignation dealt another blow to Ashley, who lost his retail chief and Sports Direct veteran of 28 years, Karen Byers, earlier this week.

Ashley has previously credited Byers as the person who was “running Sports Direct” day-to-day.

Olsen joined the sportswear giant in 2004 and was a senior member of the team when the business floated in 2007.

He was named company secretary in 2013 and was also head of legal when he stepped down.

A Sports Direct spokesman told the Press Association: “For personal reasons, Cameron has decided to return home to Australia after a great tenure here at Sports Direct.

“Naturally we are saddened he is leaving but he goes with our very best wishes for the future.”

Olsen has been replaced by Tom Piper.

His exit marks the latest in a raft of top-level departures over the past few years.

Sports Driect has also lost its chief executive Dave Forsey, chairman Keith Hellawell, acting finance boss Matt Pearson and non-executive director Simon Bentley.

The business, which is due to post full-year results later this month, has been snapping up a number of troubled retailers, including House of Fraser, Evans Cycles and Sofa.com.

Ashley wants to turn Sports Direct into the ‘Selfridges of sports’ and has similar visions to transform House of Fraser into the ‘Harrods of the high street’.