Mr Sawford resigned as leader after winning the Kettering Parliamentary seat from former minister Roger Freeman at the general election. He nominally remains in post until a new leader is elected next week.
A report due to go to council this week, written by Paul Walker, Kettering's chief executive and monitoring officer, says Mr Sawford did give a general declaration that he was employed by a training company called Phoenix.
However, there was no evidence that he had reminded the council of this at four relevant meetings held between June 1995 and October 1996. At this time, Phoenix was contracted to Kettering Centre for the Unemployed to provide training funded by the European social fund and by grant provision from the council.
'This indicates that offences contrary to s94 of the Local Government Act 1972 may have been committed.'
Mr Walker told LGC the alleged offences were 'fairly minor', involving sums of up to£2,000.