The Office of Fair Trading has confirmed it has opened an investigation into ebook pricing following complaints.
The competition regulator said it is investigating "arrangements between certain publishers and retailers for the sale of ebooks".
The OFT said it had received a significant number of complaints, but the fact that it had opened an investigation did not mean any company had broken competition rules.
The probe is being led by Andrew Groves under the Competition Act of 1998, which looks at conduct which may have a damaging effect on competition in the UK.
The OFT statement on its investigation into ebooks is here.
Some observers expected the launch of Amazon's Kindle in the UK would see a fall in prices. But it coincided with a move to "agency pricing" – essentially a resurrected Net Book Agreement which allows publishers to set retail prices for downloaded books.
Amazon now sells more ebooks than it does book books. ®
Special Report WTF... is up with e-book pricing?