SOR says the risks posed by radiation exposure from CT scans, which involves the use of X-rays to detect illnesses such as tumours, is not made clear to Clubcard holders.
In an interview with the BBC SOR chief executive Richard Evans said that the promotion was “inappropriate” and could cause “unnecessary anxiety” for people who may take up the offer unnecessarily.
But Tesco has hit back saying Lifescan, the company it uses to provide the scanning service, have qualified staff who explain the risks to customers.
Lifescan medical director, Dr John Giles, told the broadcaster that only low doses of radiation were involved, with the total dosage from a heart, lung and colon scan equivalent to living in Cornwall for 12 months.
Last month, Tesco announced Double Points, the next phase of its high-profile relaunch of Clubcard.
Following a successful trial that offered Clubcard customers double points on selected categories, shoppers can now earn double points across everything they buy in stores and online.
Analysts say the move will aim to bolster trading in the short term and halt Tesco’s sliding market share.
A Tesco Spokesperson says: “We listen carefully to customers when selecting new reward partners so that we include the products and services they feel will benefit them and their families most. As part of our health and fitness reward offers, customers over the age of 40 can exchange Clubcard vouchers towards a Lifescan health check.
“Lifescan are an experienced provider of such services employing qualified professional staff to advise on and undertake all scans and providing all customers with a full explanation of the service and any risks involved.”