Holbeach United Sports and Social Club is alleged to have owed several businesses in the town more than £40,000 when its management committee resigned last September.
The committee was chaired by Holbeach Parish Council chairman John Spencer who faced calls to stand down over the issue at a meeting last month.
Coun Spencer’s future is due to be discussed at a council meeting at Holbeach Methodist Church on Monday, despite his claims to have answered “every single question I’ve had about the club.”
The social club, based at Holbeach United Football Club in Park Road, was investigated by a group who have passed their findings on to a specialist fraud team.
A statement from the group said: “The finances of the social club have been investigated in order for us to establish its true financial position.
“Our initial investigations have uncovered, at best, a situation which the committee believes has been grossly mismanaged, leaving us no option other than to advise the appropriate authorities of our concerns.
“Our findings are that the debt the social club owes is a substantial five-figure sum and all suppliers have been advised of the situation.”
Lincolnshire Police is conducting its own investigation of the social club after details were passed to them by Action Fraud.
A Lincolnshire Police spokesman said: “An officer has been assigned and is currently working on the case, but no one has been arrested in connection with the matter.”