The group has now suspended a total of eight executives since chief executive Dave Lewis launched an inquiry into the accounting error.
"We have asked three employees to step aside to facilitate the investigation into the potential overstatement of profits in UK food for the first half of the year," a Tesco spokesperson told AFP.
"We will provide an update on the investigation with our interim results on 23 October."
The London-listed supermarket giant is co-operating fully with the FCA and other relevant authorities.
Tesco stunned investors on September 22 when it revealed that its profit for the six months to August 23 was overstated by an estimated 250 million pounds (USD 408 million, 318 million euros). It did not specify to which profit indicator this referred.
The group had previously forecast its half-year trading profit at 1.1 billion pounds.
Tesco is the world's third-biggest supermarket group after France's Carrefour and global leader, US retailer Wal-Mart.
