More money is needed for the police investigation into the £10.25m council loan to Northampton Town Football Club - with nearly £1m spent so far.
Since October 2015, Northamptonshire Police has been looking into claims of bribery, misconduct in public office, fraud and money laundering surrounding Northampton Borough Council's loan to build a new stand at Sixfields.
Figures from the end of November show Operation Tuckhill has cost £974,492 so far - but police intend to apply for additional funding from the Home Office to continue the probe and cover the costs, said to be in the 'final stages'.
Head of crime, Detective Chief Superintendent Mark Behan, said: “These allegations involve the loss of substantial public money and we are conscious of the high public interest in ensuring our investigation remains independent, thorough and as cost-effective as possible, but without compromising quality.
“It would be inappropriate for the police service not to complete such a public interest investigation on the basis of the cost."
A team of between eight and 12 officers has been working on the police inquiry into the 'missing millions' from the start with investigators travelling across the UK to gather evidence.
More than 30 people have been interviewed as part of an inquiry which has also recovered more than five million emails, text messages and computer files.
In addition, investigators have examined scores of bank accounts, collected hundreds of potential witness statements and amassed thousands of wide-ranging exhibits.
Det Ch Supt Behan said: “Northamptonshire Police always envisaged this investigation would take years to complete and, from the outset, put in place arrangements to ensure the resourcing does not compromise other areas of local policing.
“We are making a funding application to the Home Office to seek to ensure the full cost of the investigation is not borne solely by local taxpayers.
“The costs identified relate to several years of full-time investigation by a dedicated team.
"The other costs relate to the provision of the specialist services that are necessary to deal with the volume of data or complex legal issues and which are not available in-house.
“While the costs are substantial, they are in line with our expectations and, particularly given the amount of work undertaken, are lower than those incurred by others.”
Det Ch Supt Behan said they are in touch with the Crown Prosecution Service to discuss any decision-making around charges as well as the logistics concerning any future trial or trials.
Police, Fire and Crime Commissioner for Northamptonshire, Stephen Mold, said: “I continue to fully support the ongoing investigation, which has been extremely complex and resource-intensive.
"In due course, I will be asking the Home Office to support our application for additional grant funding.”
The council has spent £2.3m on its own investigation and civil suit against those involved in the deal in a bid to retrieve the money paid in 2013 and 2014.
"While a police investigation continues, we are not in a position to comment on the detail of this, beyond the information which has been provided," a council spokesman said.