Reckitt Benckiser’s (RB) attempt to acquire the K-Y Jelly brand is to come under more intense scrutiny from the UK’s deal watchdog as a result of concerns over higher prices for shoppers.

The durex owner agreed to buy the global rights of the K-Y brand from a subsidiary of US rival Johnson & Johnson in March 2014. But following an initial examination, the Competition and Markets Authority (CMA) referred the merger for an in-depth inquiry in January.

The CMA has today expressed concerns the deal could lead to higher prices for personal lubricants.

A panel, which examined the companies’ internal documents, views of competitors and retailers, sales and price data and the results of a customer survey, said the acquisition “could lead to a substantial reduction in competition”, making customers buying these products in grocery retailers and national pharmacy chains worse off.

K-Y and Durex hold almost three-quarters of the market share in supermarkets and national pharmacies.

“Consumers and retailers differentiate between these two products to some extent,” added inquiry chairman Phil Evans. “However, on balance, there seems to be enough of an overlap in the market for personal lubricants for there to be a realistic prospect of consumers facing less competition and possibly higher prices if the two biggest brands come under single ownership.”

The CMA is now calling for responses to the provisional findings and will continue to assess the evidence for a further eight weeks until it must publish its final decision by 18 August.

It has also published a list of possible measure Reckitt and Johnson & Johnson could take to ease the passage of the deal, including selling off the UK K-Y to another company or licensing the relevant rights for the UK business to another party.

K-Y is sold in more than 50 countries and brings in revenues of more than $100m.