The insurance bill for US crop claims stemming from the prolonged drought could exceed $US25 billion ($24 billion), according to new government figures.

US Department of Agriculture figures show government subsidies for crop insurance premiums this year were $US6.9 billion ($6.6 billion) – 62% of the $US11.03 billion ($10.5 billion) of premiums.

Claims until the end of October were $US3.5 billion ($3.3 billion) nationally with $US1.63 billion ($1.5 billion) going to corn farmers.

More than 80% of corn planted this year in the mid-west was covered by insurance.

Crop insurance is expected to come under scrutiny in President Obama’s second term due to the blowout in costs.

Normally crop insurance costs the US Government about $US7 billion ($6.7 billion) a year, but the drought is expected to push that figure out to more than $US15 billion ($14.4 billion) this year because the Government is shouldering most of the underwriting costs of private insurers.

In June, US senators voted to reduce the federal insurance subsidy to the wealthiest farmers and this could save $US1.1 billion ($1 billion) during the next decade.

The bill has not passed the US House of Representatives, but there is talk on Capitol Hill to cut the costs further by slashing the current premium subsidiary to private insurers.