Hard-hit savers face more income falls as banks and building societies make further cuts to their interest rates.
The average return on a one-year fixed-rate account has fallen from 2.77% to 2.57% in the past two months while the typical two-year fix has dropped from 3.29% to 3.01%, according to website Moneyfacts.
A string of providers have made reductions to some of their savings rates over the past weeks or so, including Halifax, Santander and the Principality Building Society, the consumer help website said.
Meanwhile, the most competitive rate on a five-year fixed-rate bond has fallen to 3.98%, compared with 6.56% five years ago, with many market-leading deals being withdrawn very quickly after launch.
Analysts suggested that returns on savings pots could edge lower still as banks become less reliant on attracting savers' deposits a result of the Bank of England and Treasury's recently-launched funding for lending scheme.
The £80 billion scheme was launched at the start of August and gives banks access to cheap funding to unclog the flow of credit to households and businesses.
Kevin Mountford, head of banking at comparison website Moneysupermarket, said: "The main focus of many banks has been attracting retail deposits through competitive higher rates because they have been unable to access wholesale funding given the tough financial conditions and the eurozone crisis.
"Cheap loans from the Bank of England through funding for lending should give them a way to reduce their reliance on deposits. However, this could have a negative effect on savers."
Savers have already been struggling to find any accounts to give them real returns on their cash amid high inflation and more than three years of the Bank of England base rate being held at a historic 0.5% low.
They have lost about £85 billion since 2007 as a result of interest rate cuts, according to research from Nationwide, which used industry figures from the Bank of England and Moneyfacts to compile its research.