Confidential audits offer a rare glimpse at some of the billings that raised questions in the minds of the claims administrator.
Among them are claims with missing or mismatched paperwork, unauthorized prescriptions and refills and excessively high dispensing fees.
The Canadian Press obtained hundreds of pages of audits under the Access to Information Act as part of a months-long investigation into alleged abuses of federal money for aboriginal health care.
The audits come from Mississauga-based Express Scripts Canada, which administers claims for dental, medical supplies and equipment and pharmacy benefits on behalf of the Non-Insured Health Benefits program.
The NIHB program provides health-benefit coverage to eligible First Nations people and Inuit when they are not insured by private or provincial plans.
The documents show Express Scripts Canada has audited pharmacies and other types of service providers in every province and territory.
In some cases, honest mistakes or simple oversights, such as forgetting to submit paperwork, appear to explain the billing issues. Other times, pharmacies were asked to repay thousands of dollars for improper billings.
An Express Scripts Canada audit alleges one Yukon pharmacy billed for items not covered by the NIHB program and split prescriptions to charge additional dispensing fees. The drug store was asked to pay back more than $25,000.
Another audit alleges a New Brunswick pharmacy billed the NIHB program for doses of methadone it never actually dispensed to patients.
Express Scripts Canada declined an interview request.
"As a service provider to Health Canada, Express Scripts Canada does not feel it would be appropriate for us to provide comment on services that we provide to our client," company spokesman Paul Stulberg said in an email.
However, the government official in charge of the NIHB program offered some insight into the audits.
"It could be a large variety of things," Sandra Bruce, the program's director-general, said in an interview. "Maybe the pharmacist pressed the wrong button and when you do your audit checks right, it goes 'hang on, that button doesn't match.'
"So that's one aspect of what Express Scripts does for us. On another level, we contract with them so that they will go in and they will do up to 140 audits of providers each year."
The company also hires an auditor to check its own work, she added.
Only a handful of cases have been turned over to law-enforcement authorities, Bruce said.
"Pretty small amount, actually. If you think about it, we have 25,000 service providers. We actually have five cases of fraud on the go since 2006," she said.
"Now that's not to say that there's not administrative anomalies, misunderstanding or whatever that we don't go back and negotiate or deal with. But in terms of where it's processed into the system and gone into the fraud kind of approach with our friends in the law enforcement and through that part of the system, it's only five."
That's not counting cases where the federal government has gone to court to recoup money from service providers — sometimes, millions of dollars.
Ottawa is suing a Manitoba pharmacist and his former drug store for $3.1 million over allegations they fleeced the aboriginal health-benefits plan.
Another Nova Scotia pharmacist and his numbered company face a $1.36-million lawsuit over allegedly "fraudulent" claims.
And the federal government is trying to recover $355,520 from the former owners of a Saskatchewan pharmacy.
None of the allegations have been proven in court.
Bruce said Health Canada takes allegations of wrongdoing seriously.
"We put the health of our First Nations first. But we have rigorous programs. We've very conscious of the public purse, and we're always doing things to refine our surveillance programs," she said.
"We're always working to make sure that we tighten everything up around the edges. We examine what we're covering, how we're covering it, and the processes. So it's a very rigorous program."