When Olukunle Adetunji walked free after nearly a year in immigration detention, he hoped it would mean he could pick up from the moment he was plucked from life with his wife and children — instead, he faces a prospect worse than being behind bars: being permanently separated from his family.

On Monday, the father of three is filing an application to stay a deportation order he and his wife say should have never been issued. 

"The children were happy, just July 19 I got out. All of a sudden they're taking me out of their life again," he told CBC News. "Nobody's prepared, the children are already enrolled in school … Everything just came last minute."

For immigration advocates, the case underscores not only what they say is the unfair practice of indefinite immigration detention but the pitfalls of release.

"Olu's case is a really important example of the flip side of being released from detention, which is deportation," said Swathi Sekhar, a lawyer for the End Immigration Detention Network.

'They ambushed us'

"That is something we equally need to stand up against because, look at the impact on families, of someone finally getting of jail," Sekhar said. "You think you're going to be able to start a life and then you're physically removed from this country."

​Adetunji's ordeal began in 2012 when he came to visit Canada and decided he wanted to stay. Before long, he met Kimora and by 2014 they were married with a baby on the way. Adetunji acknowledges he'd stayed illegally. He was sent back to Nigeria and remained there for two years.

But with his family half a world away, he desperately wanted to return. A sponsorship application for someone in Nigeria regularly takes three to four years, his wife says, and waiting was not an option.

 Olukunle Adetunji

On Monday, Olukunle Adetunji, a father of three, is filing an application to stay a deportation order he and his wife say should have never been given. (John Sandeman/CBC)

In 2016, Adetunji returned by illegal means. The pair decided he would apply to stay in Canada on compassionate grounds and they could finally be together again — that was the plan anyway.

It all came to a screeching halt one day when the couple was driving in Toronto. 

"They ambushed us, a whole bunch of unmarked cars ... surrounded us and they chased us down the street," Kimora Adetunji recalled.  "They told him to get on the ground, pulled out guns, we didn't know who it was."

'I didn't want them to know he was in jail'

At the time, Kimora, who herself was detained as a child when her family arrived in Canada in 1992, wondered if they'd been caught up in some kind of gang violence.

"Later, they told us it was the Canadian Border Services Agency (CBSA)."

From that moment on, Adetunji found himself behind bars — first at the Maplehurst Correctional Centre for about a month, then to Lindsay for a few more, then to a facility in Scarborough and finally to Toronto's Immigration Holding Centre. 

"I was just picked up on the street one day and I was put in the detention centre," he said.

Meanwhile Kimora came up with excuses to give to her children about why their father wasn't home. "I didn't want them to know that he was in jail."

It took 10 months in detention at a series of maximum security provincial facilities before Adetunji was freed. Meanwhile, Kimora says the pair filed an application for him to become a permanent resident on humanitarian and compassionate grounds. 

The day he was released, Adetunji claims, a lawyer for the CBSA told him they wouldn't push for him to be deported until there was a decision about his application for permanent status.

"Then suddenly a couple of weeks ago they just turned around and said, 'We're actually going to deport you,'" said Swathi Sekhar, a Toronto-based lawyer for the End Immigration Detention Network. 

Applications reviewed even after removal

Scott Bardsley, spokesperson for Minister of Public Safety Ralph Goodale, would not discuss the specifics of Adetunji's case.

But in an email to CBC News, he said the decision to remove someone from Canada isn't taken lightly. Applications to become a resident on compassionate grounds don't postpone removals, he said, but the government continues processing applications even after a person has left Canada.

Immigrant Detainees 20160711

Public Safety Minister Ralph Goodale says he's heard the concerns about Canada's immigration detention program and wants improvements. (Adrian Wyld/Canadian Press)

"As the Federal Court has observed, often individuals who end up in prolonged detention have been given many chances, but failed to co-operate with those who protect the integrity of our immigration system," Bardsley said.

Anyone ordered removed from Canada is entitled to due process and all such orders are subject to "various levels of appeal."

Sekhar says it's almost impossible to win an application from outside the country and hopes Monday will bring good news. 

"It could be that a judge looks at this and actually decide, you know what, it would be reasonable for this man who has three Canadian children, who has a Canadian wife who has been living here, for him to stay here," Sekhar says. "That's the outcome we're hoping for."

The Adetunjis also hope if the CBSA won't reverse its position, a judge will help keep their family together. But while they hope for good news Monday, they may not know until moments before his scheduled flight. 

As she waits, Kimora says she's disturbed something like this can even happen in Canada. 

"With all the stuff that's happening in the U.S. with DACA, we just turn our nose … We look at [it] as if it's so horrible, but people don't know that the same kind of system is right here."

With files from Natalie Nanowski