Samsung has admitted that negative online reviews of Taiwanese rival HTC were written by their employees.
After evidence came to light of the practice, the Korean company admitted the "unfortunate incident" which was allegedly done by paid students.
The reviews were brought to light by the website TaiwanSamsungLeaks who accused the company of "evil marketing".
Backing up their claims were documents purportedly from Samsung's hired marketing firm cataloguing the fake posts.
The Taiwanese Fair Trade Commission has launched an investigation.
The tech giant could be fined £547,000 - small change for a company valued at over £131 billion last year, but still embarassing.
Samsung released a statement saying:
Samsung Electronics remains committed to engaging in transparent and honest communications with consumers as outlined in the company's Online Communications Credo.
We have encouraged all Samsung Electronics employees worldwide to remain faithful to our Credo.
The recent incident was unfortunate, and occurred due to insufficient understanding of these fundamental principles.
Samsung Electronics Taiwan (SET) has ceased all marketing activities that involve the posting of anonymous comments, and will ensure that all SET online marketing activities will be fully compliant with the company's Online Communications Credo.
We regret any inconvenience this incident may have caused. We will continue to reinforce education and training for our employees to prevent any future recurrence.
The global smartphone market is worth billions of pounds, making competition fierce.
Samsung and Apple dominate the market with a 52% marketshare. HTC are struggling to gain 2% according to Gartner.