A David vs Goliath battle is brewing between the multi-billion dollar Richemont Group and a company which has "very weak to nil reputation in Australia".
Richemont, owner of luxury giants Net-A-Porter and Mr Porter, has threatened legal action against a local online store over its web design.
Richemont lawyers detailed the alleged copyright infringement in a letter to Sydney-based Mr Shirts on February 4.
The letter claimed Mr Shirts operates a website with "remarkably similar" layout and content to Mr Porter.
This includes the overall look and theme of a newspaper and "minute details" in layout and organisation.
Specifically, it alleged both sites feature black fonts on a white background, the term 'Mr', a large product advertisement, oversized thumbnails of additional products and similar search, social media and sign-in links.
In its response, issued on February 25, Mr Shirts played down the allegations in signature style.
"Are you suggesting that Mr Porter has mimicked the front page of a newspaper and that we have in turned mimicked you? Does Rupert Murdoch know about this?"
Mr Shirts confirmed it registered its domain in April 2013, some 12 months before the registration of Mr Porter.
"As you probably don't know, Mr Shirts has been trading for little over 12 weeks; has very weak to nil reputation in Australia; which is home to 22 million people - being less than one-third of one per cent of the world's population.
"We also don't rank in Google, Yahoo or Bing, we have zero employees, but do offer the highest quality business shirts at the lowest prices & that's just the start!"
Its response also noted Mr Shirts was built on the Magento ecommerce platform, used by over 200,000 merchants.
Mr Shirts reference websites such as Harper's Bazaar, Gant and Warby Parker, all of which allegedly use the platform and utilise a large featured product advertisement on their homepage.
The letter rejected all claims of copyright infringement and ended with a pointer to its sales performance.
"In 2012 we had a turnover of $0, but Mr Shirts and I enjoy a good handicap."
Both the letter and response have been made available on the Mr Shirts website here.
Mr Porter and Richemont had no comment to make when contacted by ragtrader.com.au.