OTTAWA —The Conservative government has spent more than a quarter of a billion dollars over five years to continue its often criticized practice of detaining potential immigrants and refugee claimants.

“We don’t know what led to these detentions, we don’t know when these detainees will be released. We need to start shedding light on this,” said New Democrat immigration critic Andrew Cash.

“The government has spent more than $250 million detaining eight- to 10,000 people per year including hundreds of children, and there is no oversight.”

READ MORE: 16×9 investigation into how the CBSA deals with some ‘inadmissibles’

Costs related to detaining migrants, asylum seekers or immigrants have increased over the three most recent years with available data, despite a decreasing number of detainees being held across the country, according to Canadian Border Services Agency figures recently published.

Story continues below advertisement

Between 2012-13 and 2013-14, costs of detaining individuals under the Immigration and Refugee Protection Act increased more than 10 per cent despite a 13 per cent decrease in the number of people held over the same time period, according to the figures tabled in the House of Commons late last week.

In an email to Global News, the border agency said the national average cost per day of detaining an individual is currently $292.41.

“The rise in costs for immigration detention is due to a number of factors, including an increase in operations costs,” a spokesperson wrote, offering examples like per diems costs, contracted guards and food services.

The costs also increased on account of “a very slight” increase in the average number of days in detention, the spokesperson wrote.

Story continues below advertisement

READ MORE: Canada’s immigration detention violates rights, report says

Upon receiving the information he requested from the border agency, Cash said the first thing to strike him was the number of children in detention.

According to the figures, between 196 and 287 people younger than 17 years old were detained alongside their parents or family between 2010-11 and 2013-14; another 17 to 31 were detained without any adult around during the same time frame.

In an email, the CBSA assured it holds the best interests of children top of mind, though the psychological effects on detained children are well documented.

READ MORE: Jimenez suicide inquest reveals errors made by private security firs hired by CBSA

Canada’s treatment of refuge-seekers has been increasingly under the spotlight, most recently with the case of a man who died while being held in Ontario by the Canadian Border Services Agency. It was revealed last week that the man was a mentally ill and diabetic Somali refugee who had already spent three years in prison, without prospect for release.

“It’s clear to me that it’s time for an overhaul to the way in which we approach immigrant detention in this country,” Cash said. “And we need to start with greater transparency and oversight.”

Story continues below advertisement

Regardless of whether someone’s refugee claim is bogus or if they violated conditions of their immigration status, people on Canadian ground all have an equal right to due process and legal counsel, and cannot be arbitrarily detained.

READ MORE: Canada’s Unwanted – Non-citizens paid to leave, jailed without charge, die in secret

Whether a person trying to enter Canada is detained at the discretion of the country’s border guards, a CBSA agent must have reasonable grounds for referring an individual to a detention centre or jail; the agent must believe, for example, the person is a threat to public safety, holding false or inadequate identification or otherwise inadmissible.

When a guard decides to detain someone, the Immigration and Refugee Board must review the decision within 48 hours and decide whether to release the individual or keep them detained.

READ MORE: Iranian refugee’s jail ordeal reaches 173 days – with no end in sight

In an email sent Tuesday, the border agency noted that once those initial 48 hours have passed, releasing a detainee is at the discretion of the refugee board.

Still, the border agency is responsible for the detainees.

A Global News investigation published earlier this year showed the CBSA routinely detains people indefinitely in jails and detention centres on no charge, often with limited access to family, legal counsel and third-party monitoring agencies.

Story continues below advertisement

READ: Cold, ill-fed, terrified: Ex-detainee recalls Lindsay jail ordeal

According to the figures released in the House of Commons this month at Cash’s request, the average length of stay in 2013-14 was 23 days, though a majority of detainees was released within 48 hours. Of the detainees currently in the system, 38 have been detained between one and two years, 16 for anywhere between two and five years, and four for more than five years, according to the CBSA.

“It’s deeply concerning to see that what should be an option of last resort is actually being used to detain large numbers of people on a regular basis,” the NDP’s Cash said. “And it’s especially concerning when we’re seeing cases of detainees who don’t have access to adequate levels of health care or mental health care.”

With a file from The Canadian Press