Shop price inflation rose to 2% in April, up from the 1.2% recorded in March.
Food inflation increased from 1.2% in March to 2% last month, while non-food inflation edged up to 2% in April from 1.3% in March.
The British Retail Consortium-Nielsen Shop Price Index found that costs rose due to increases in commodity prices in items such as oil and cocoa, but that the overall rate of inflation is still below the rates recorded in December and January.
BRC director general Stephen Robertson said: “With commodity prices going up food prices were almost bound to rise when compared with last month’s three-year low.
“Even so, food inflation is a quarter of what it was this time last year while some produce - milk, cheese and eggs - is actually cheaper than 2009.
“Oil, which is up 70% over the year, also influenced some non-food prices. VAT is also higher than a year ago.
“But the main effects of rising costs and the weak pound have now been felt. With demand still weak, shop prices should be more stable in future months, as long as there are no more big shocks.”