Pricing tactics and the alleged use of "land banks" to prevent rival retailers opening new outlets have been called into question by the Office of Fair Trading.
Analysts suggested that Tesco had the most to lose from an inquiry because of its position as number one in the sector - both in terms of its property portfolio and its continued dominance of market share.
Retail analyst Nick Gladding, of industry experts Verdict Research, said the size of Tesco put it in a "unique position".
Next month the OFT is due to decide whether or not to refer the sector to the Competition Commission, with a subsequent inquiry expected to take up to two years.
"It could be bad news for Tesco," said Mr Gladding.
"But Tesco could make a strong case that it has the same right to acquire land as anyone else and it is up to local authorities to decide if they want a Tesco in their area.
"Tesco is a special case - other retailers do not have nearly as much land as Tesco."
Tesco said it was confident that the OFT's observations were "misplaced" and insisted it did not have a land bank.
"All land that we purchase we use to develop new stores or extend existing stores," a spokesman said.
The provisional findings last month came amid growing criticism of supermarkets, which have been blamed for falling sales on the high street and the closure of smaller convenience stores unable to compete with the might of Tesco, Sainsbury's, Asda and Morrisons.
The Association of Convenience Stores hailed the OFT's move as a "landmark ruling" for independent retailers and consumers.
And responding to Tesco's "booming" profits today, Friends of the Earth said it was "time to put the brakes on the Tesco juggernaut" as consumers, farmers and the environment suffered.
Campaigner Sandra Bell said: "The Government and competition authorities must recognise the value of small shops to local communities and create an environment that allows retail choice to flourish."
But today's record figures show that Tesco remains popular with shoppers despite the criticism, which the company dismissed.
Tesco said: "We look forward to the competition debate and a prompt and speedy conclusion which will confirm the OFT's overall comment that consumers have benefited from competition between supermarkets and their expansion into the convenience sector, through falling prices, increased choice and improved quality.
"We are confident that once the other observations in the report are explored, the regulators will find that they are misplaced."
Mr Gladding said: "Tesco is in a defensive position and it is aware of public opinion changing and is sensitive to that.
"It needs to present itself on the side on the consumer and by extending choice by raising the standard of retailing.
"People criticise Tesco for effectively closing down local stores which cannot compete, but Tesco offers lower prices and in many cases better choice than smaller stores so it has got quite a strong argument for being allowed more stores.
"As far as the land banks are concerned, Tesco is in quite a unique position because it did build up a lot of land in the late 1980s and early 1990s when it wasn't a real issue.
"There is no reason why retailers cannot build up land banks, there is nothing wrong with that, and other retailers have land banks, but they are not as big as Tesco's."
He said Tesco's continued success mirrored its understanding of the consumer.
"It is very effective at developing products and services that meet its consumers' needs.
"It has a very good understanding of what people want from it.
"It became more price competitive and realised that lower prices were a very effective way of increasing customer share. Lower prices are compensated for by higher customer numbers."
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