Advocacy groups are again calling for "robust, independent and external oversight" of the country's border service following reporting by CBC News on misconduct at the Canada Border Services Agency.

CBC News recently reported that the agency investigated around 1,200 allegations of staff misconduct between January 2016 and the middle of 2018. Alleged offences recorded in the records released to CBC News include sexual assault, criminal association and harassment.

"We were not surprised," said Josh Paterson, executive director of the British Columbia Civil Liberties Association. "My main reaction was, this just makes [it] even clearer why there needs to be independent oversight for this agency."

The BCCLA is one of three groups behind a letter to Public Safety Minister Ralph Goodale asking when the government will introduce CBSA oversight legislation. The presidents of the Canadian Council for Refugees and the Canadian Association of Refugee Lawyers also signed the letter.

The CBSA's sweeping powers include the right to search travellers, use firearms and conduct deportations. It's the only major federal law enforcement agency without external oversight of employee conduct.

The groups' letter also cited a recent CBC News report that said the agency had lost a USB key containing a refugee claimant's personal information.

"We have had our own experiences of bringing very serious complaints to the CBSA, and they go nowhere, because there is no independent accountability measure," said Janet Dench, executive director of the Canadian Council for Refugees.

The groups call in the letter for an oversight body that can "investigate complaints" and "conduct proactive assessments of CBSA policies and practices."

Dench said the oversight agency also should be able to hear complaints from third parties, such as non-government organizations.

"Often, we are in a position to say, 'Look, we've seen a pattern of disturbing behaviour, or we have heard from somebody who's not in a position to complain themselves,'" she said.

Scott Bardsley, a spokesman for Goodale, sent CBC News a statement Thursday that was identical in some respects to a statement the department issued last month.

"CBSA officers processed 95 million travellers in 2017, and only a very small number of these interactions led to a formal complaint," Bardsley said in an email.

Bardsley said in a statement last month that the government was "working on separate legislation to create an appropriate mechanism to review CBSA officer conduct and conditions, and handle specific complaints."

But the government's window to introduce legislation is closing, with a general election due this fall.

"The CBSA ... does not have independent review of officer conduct, and that is a gap that definitely needs to be addressed," Goodale told a Senate committee in 2016.

Following the recent CBC News story, Goodale said the government is preparing legislation that would create "another unit ... that looks specifically at the issues of officer conduct or incident investigation.

"We continue to work at it as rapidly as we can."