The Competition and Markets Authority (CMA) said it was to examine the German-owned firm's UK entities over concerns consumer law had been breached.

Its concerns included the use of countdown timers and claims about time limits to misleadingly imply that discounted prices would soon end.

The watchdog stressed its inquiry was at an early stage and there should be no assumption that the law had been broken.

The company was yet to comment.

The CMA said it marked the start of its wider enforcement work focusing on so-called Online Choice Architecture to tackle potentially harmful online sales practices, including pressure selling tactics such as urgent time-limited claims.

These include countdown clocks, where sellers put pressure on shoppers to buy quickly, and eye-catching discount offers such as "50% off" claims when the real price reduction may not be as great as claimed.

Earlier this year, the watchdog revealed that 71% of people shopping online have encountered misleading selling tactics.

CMA interim chief executive Sarah Cardell said: "With the rising cost of living, genuine deals are worth shouting about - but companies using misleading 'sale' prices or fake countdown clocks can put unfair pressure on people to buy and could break consumer law.

"The CMA is today reminding businesses they should not use urgency claims to mislead consumers and, if they do, they face the risk of CMA action.

"This investigation into Emma Sleep is just the start of our work into potentially misleading online claims and all sectors are under scrutiny.

"Companies should take note: look at your own practices and ensure they're in line with the law."