The voucher allowed customers to purchase items for free if the item was priced below £15.
The deal was posted on HotUKDeals, leading to numerous users to place orders with the online retailer using the discount code.
As a result, Play.com crashed and was down for a brief period of time.
The website has now been restored with the code expired, although it is unclear whether or not Play.com will honour the successful orders.
Play.com posted: "Thanks for your feedback and comments. This code was unfortunately raised in error, and has now been taken down.
"We are currently investigating the technical issues surrounding this. Please bear with us whilst we solve the issue, and thank you for your patience."
> Play.com bought by Japanese firm Rakuten for £25m
> Law firm offers 'divorce vouchers'