According to Moneyfacts, savers taking out a fixed rate bond today will receive up to 23.3% less interest than they would have nine months ago.
Savers investing the average amount nine months ago would have received £1,209 in interest, compared to just £978 today.
Michelle Slade, Spokesperson for Moneyfacts.co.uk, commented: "Providers are focused on mortgage lending and as they strive to attract new business by reducing mortgage rates, they are in turn cutting savings rates to balance the books.
"Uncertainty over when bank base rate will rise means most savers are only taking a short term view, but they are being punished by the biggest reductions in rates.
"At 2.62%, the average rate on a one year bond stands at an all time low.
"Prudent savers who rely on the interest from their savings to supplement their income continue to be hit the hardest.
"Inflation also continues to take its toll on savers and is effectively depreciating the value of savers' capital.
"Savers hoping for incentives from last month's Budget were left bitterly disappointed and many continue to feel their needs have been forgotten during the credit crisis.
"With a change in bank base rate still predicted to be a little way off, the situation for savers is likely to get worse before it gets better."
