OTTAWA -- The Canada Border Services Agency is not keeping a close enough eye on exports, causing high-risk shipments -- including illegal drugs and possibly illicit weapons technology -- to leave the country undetected, says auditor general Michael Ferguson.

In his latest series of reports examining the efficiencies and failings of various government departments, the federal watchdog finds the border agency is not reviewing all export declarations and not examining many shipments flagged by its own internal system -- or by warnings from other departments.

Up to 20 per cent of high-risk exports identified by the agency's centralized targeting units were allowed to pass without inspection, according to the audit, tabled Tuesday in Parliament.

It's a troubling situation, said Ferguson, who stopped short of calling it a national security concern.

"The government has made international commitments related to non-proliferation, and controlling technologies that could be used for weapons technology," Ferguson told a news conference.

"So, I think it's very important we have in place the measures to do that."

It is "possible there could be some technologies leaving the country that shouldn't be," he added.

Much of the breakdown relates to staff levels, and the fact the border agency focuses much of its resources on controlling imports. In some locations, inspections cease entirely if a single staff member goes away on vacation.

"We also found that the agency did not always conduct targeting and examinations during all hours and days when export shipments move," the audit said. "This meant that non-compliant shipments were exported undetected."

When the agency did detain shipments, the audit found, it was holding on to legitimate goods far too long, in some cases costing businesses their contracts.

While goods valued under $2,000 do not need to be declared, they can be subject to random inspection -- but the audit determined they often are not because of a shortage of staff.

Small, undeclared parcels are a popular means for drug traffickers to get their illicit products out of the country; according to Ferguson's report, hunting for those shipments is not a priority under the current system.

"The agency had identified illegal drugs being exported out of Canada as a high-risk area; it made several drug seizures during the period of our audit," it said.

"But agency officials told us that the limits on their examination authorities reduced their effectiveness in preventing the export of illegal drugs. This limited authority, together with limited resources, resulted in the agency's not setting export of illegal drugs as an examination priority."

Public Safety Minister Ralph Goodale tried to put the best face on the report.

"Overall, the review of CBSA was very positive," he said after the report was released. "Where there was criticism, CBSA has accepted that criticism and has a plan in place to implement the remedial measures by the end of this year."

But Ferguson said the agency receives a mish-mash of customs declarations and that the whole system should be electronic.

In 2014, the agency received data on about 787,500 electronic forms declarations submitted through the Canadian Automated Export Declaration (CAED) system -- an outdated network that was due to be replaced years ago. Additionally, it received at least 44,000 paper declarations.

Exporters intent on evading the inspection system seem to know that all they have to do in order to slip past is to file the paperwork right at the deadline. Declarations must be submitted at least two hours before shipments are loaded on planes and at least 48 hours before loading onto ships.

"We were told that about one third of targets were not examined because the agency's local office received information about the targets too late--that is, after the shipments had already left or been loaded on planes and ships," said the audit.