The industry's efforts to combat fraud are contributing to a fall in the volume of theft claims, according to Grant Thornton.
ABI statistics on gross incurred claims revealed that over the past ten years claims for theft have steadily reduced from £530m in 2003 to £510m in 2004.
For the first nine months of 2005, the total number of theft claims was £334m.
The drop in gross incurred claims has been mirrored by a 20,000 reduction in the volume of claims made.
Angus Tucker, Grant Thornton's insurance claims solutions director, said: "There is a noticeable downward trend in the area of theft claims.
"I believe this is because the insurance industry has introduced a lot of initiatives to combat fraud."
An ABI spokesman said the industry's focus on detecting fraudulent claims could be a factor in the reduced theft figures, but was not sole reason for the reduction.
He said the figures would help the ABI to determine trends for use in research.
The spokesman added that a number of factors, including economic performance, could have contributed to the decline.