Russian authorities have leaned on shops to keep prices steady but newly released data shows inflation pricking up on goods most affected by the government's ban on EU and US food imports.
A senior government official also acknowledged that non-sanctioned suppliers were raising prices sharply.
Information released by the Rosstat statistics agency on Wednesday showed prices rose by 0.1 per cent last week from the previous week, pushing up the annual inflation rate to 7.6 per cent.
Price rises on foods that Russia imports heavily have also begun to accelerate.
Prices on fresh and frozen chicken rose by 1.4 per cent last week, after having climbed 0.9 per cent the previous week and 0.8 per cent the week before that.
Pork prices rose by 0.9 per cent last week, up from the 0.5 per cent gain from August 12-18 and a 0.2 per cent gain in 5-11 August.
Price increases on frozen fish and cheese also accelerated.
Russia slapped an immediate ban on most EU and US food imports at the beginning of August in retaliation for Western sanctions over Moscow's perceived support for pro-Russian rebels fighting in eastern Ukraine.
Australia, Canada, and Norway also fell under the ban.
With the country importing about a third of its food, average Russians were concerned about price rises even if they supported taking retribution against the West.
Government officials expressed confidence that other foreign suppliers can quickly be found. This, together with increases in domestic output, should ensure no shortages, they said.
In measures reminiscent of communist times when prices were strictly controlled, the government has stepped up price monitoring, requiring stores to report on stocks, and has been leaning on shops and suppliers to hold off passing on cost increases.
Russian authorities have been engaged in intense efforts to find alternative food suppliers in other countries, in particular from South America.
A senior official noted however Wednesday that some suppliers were trying to raise prices.
"It is an especially difficult situation with Latin American countries, which want to step up sales, but of course at the same time getting the most for themselves, and prices have gone up quite sharply," Deputy Prime Minister Arkady Dvorkovich said.
