Employment Insurance fraud has hit a five-year high — a sign for federal officials that efforts to root out wrongful payments are working.

Public accounts documents released this month list more than 104,000 incidents of fraudulent EI claims totalling almost $177 million in the 2017-18 fiscal year.

It marks the fourth year that fraud figures have increased in the wake of efforts by Employment and Social Development Canada to fine-tune the department's ability to identify and deal with fraud.

Officials expect eventually to collect $132.8 million of the wrongful payments identified in the fiscal year that ended in March, and plan to write off about $74,000 of them.

The amount of fraud is minuscule compared to the overall amount spent on benefits for the unemployed, for new parents on leave, for workers who need time off due to serious illness and for those who must stay off the job to care for an ailing family member.

EI spending between April 2017 and March 2018 topped $19.7 billion. The value of fraudulent claims amounted to less than one per cent of total spending.

"The government is committed to deliver these important benefits to Canadians when they need it most while protecting the integrity of the system from fraud and erroneous overpayment," an ESDC spokesman said in an statement.

"The department has made investments to improve its efforts to identify fraud, including adjustments to its risk-based analytical models. These efforts have contributed to this increase."

In general, the later the government detects fraud or overpayments, the harder it is for it to recoup funds.

The government must collect the money within six years of identifying a wrongful payment; if it can't, officials write it off. The clock starts when an incident is flagged, but the deadline to collect can be extended if, for instance, the debtor goes to court.

A review of the annual spending documents show EI write-offs have been on a three year slide, hitting $43.6 million in fiscal year 2017-2018.

Two years ago, ESDC rejigged the automated system that detects fraud in hopes of identifying more and larger cases of incorrect payments.

The program considers some 100 variables to calculate the chances that someone has received too much money, either by accident or through fraud.

Similar efforts have hit other programs, including Old Age Security benefits that cost $38.4 billion last fiscal year.

OAS fraud dropped between the 2017-18 fiscal year and the preceding 12-month period, going from 16 cases worth $1.2 million down to 10 incidents worth $494,490 — a six-year low for both figures.

Likewise, Canada Pension Plan fraud has been on a downward trend that's now into its fifth year.

Officials found five cases, worth $92,010, but half of that sum is not expected to be recovered.