The investigation into an accounting scandal at global retailer Ahold could be widened to include other major US food companies.

The Wall Street Journal suggested that probes into firms such as Sara Lee and ConAgra Foods could rock the $500bn US food industry and have broad ramifications for the way food companies sell their products to distributors.

In February Ahold unearthed accounting irregularities at its US Foodservice unit which overstated profits by more than $500m following discrepancies in accounting for vendor allowances.

A spokesman for ConAgra told the WSJ only that "we are aware of the investigation concerning Ahold".

The newspaper added that a Sara Lee spokeswoman said the allegations were "untrue" and "unsubstantiated”.