A spokesperson for Dr Martens confirmed to Just Style Sparta Capital has been building a stake in the brand.

However, while reports from Sky News suggest Sparta has “quietly accumulated stock worth tens of millions of pounds” in the London-listed brand, the spokesperson said he was unable to confirm the amount.

Sparta Capital has reportedly been engaging with Dr Martens board in an attempt to improve its financial and operating performance and according to city sources cited by Sky News, it is now a top ten shareholder in the footwear brand.

The media report said one institutional investor suggested that Sparta was likely to have pressed Dr Martens to launch a buyback, with the company announcing a £50m initiative to do so alongside its results earlier this summer. The fund manager is said to have urged the company's board to focus on improving the execution of its strategy and addressing the problems at its US distribution site more robustly.

In an email to Just Style, a spokesperson for Dr Martens said it had begun to address the issue with the LA distribution centre “as soon as it emerged last year” which is “now completely rectified and has been for some time.”

Just Style also understands the share buyback programme was announced independently and prior to Sparta’s intentions becoming public.

“We engage with all our shareholders on a frequent basis and met with Sparta as part of the regular roadshow after our full-year results.”

Sparta did not reply to request for comment.