Frasers Group Plc, which owns House of Fraser and Sports Direct, declared it now owned 5.1% of the online fashion website in an announcement on the London Stock Exchange.

The group is now the fourth largest shareholder in ASOS as a result of the latest share purchase.

Frasers Group had already acquired a smaller stake in the retailer earlier this year.

ASOS has been going through a troubled period. Just last week it reported slowed sales and a £32m pre-tax loss in the year to August.

It recently approached the banks behind its £350m revolving credit facility to seek an amendment to its borrowing agreements.

Also on Monday morning came the announcement of Frasers Group's increased ownership of German fashion company Hugo Boss.

Frasers Group reported it owned 4.3% of Hugo Boss stock directly and an additional 28.5% through put options, a financial instrument. Owning put options does not mean gaining increased voting rights in a company and does not contribute to increased ownership.

It now owns £840m in Hugo Boss shares.

Frasers Group has stakes in household clothing brands including Everlast and Jack Wills.

Over the summer, it acquired fast fashion brands I Saw it First and Missguided.

In the Hugo Boss announcement on Monday morning, Frasers Group said it "continues to see opportunities that strengthen Frasers Group's brand proposition".

"Frasers Group has extensive ambitions to grow the business inside and outside of the UK and is constantly exploring the potential for further expansion."

In September, Mike Ashley said he was stepping down as a director of Frasers Group, the retail empire that has its origins in Sports Direct, the business he founded. He remains its controlling shareholder.