The Office of Fair Trading has called for information to explore the extent to which businesses are monitoring online shoppers and using the data to target them with personalised prices.
Many businesses monitor consumer behaviour online, collecting and recording information about individual shoppers' purchasing habits, websites they have visited and the items and services they have looked at, as well as the type of device or internet browser they use.
The trading watchdog has said it wants to look at how businesses use such consumer information, including whether they change the prices they offer individual shoppers as a result.
The OFT will also consider business and technological developments in the online shopping market, consumers' understanding of how their information is used and whether they are being treated unfairly in law as a result of any firms using this practice.
Clive Maxwell, OFT's chief executive, said in a statement: "Innovation online is an important driver of economic growth. Our call for information forms part of our ongoing commitment to build trust in online shopping so that consumers can be confident that businesses are treating them fairly."
The OFT is particularly concerned about whether consumers have enough control over what data gets passed/sold on to third parties - and whether firms are making it clear what data they need, compared to what they are simply selling on to others.
"We know that businesses use information about individual consumers for marketing purposes. This has some important potential benefits to consumers and firms. But the ways in which data is collected and used is evolving rapidly," said Maxwell.
"It is important we understand what control shoppers have over their profile and whether firms are using shoppers' profiles to charge different prices for goods or services."
The OFT will be gathering information over the next six months and would like to hear from interested parties including online retailers and software providers. It will publish its findings in spring 2013.