The Home Office said the migrants will begin detention within weeks in preparation for their first flights taking off for Rwanda.
And yet comes The Guardian reported The transfer of people to detention centers will begin on Monday.
In response, the Ministry of Interior said that the government was “entering the final stage” to activate this policy.
Glasgow-based human rights lawyer Amer Anwar said he had been informed that the arrests would begin on Monday.
Prime Minister Rishi Sunak said the first flight should take off within 10 to 12 weeks.
A Home Office spokesman said that preparations at some stage would “inevitably” include detaining people.
The spokesman added: “It would be inappropriate to comment further on operational activity.”
According to The Guardian, officials plan to detain asylum seekers who attend routine meetings at immigration services offices, and will also pick up people nationwide in a major two-week exercise. These people will then be transferred to detention centres.
These details have not been confirmed by the BBC.
The policy, which will see some asylum seekers sent to Rwanda, seeks to deter people from crossing the canal in small boats.
In response to the Guardian report, Sonia Setts, chief executive of the charity Freedom from Torture, told the BBC: “Make no mistake, this latest attack on refugees by this government will further traumatize people who have fled torture chambers in search of safety and protection.” An opportunity to rebuild their lives in the UK.
“We know from our clinical services that even torture survivors who are completely safe from harm tend to live in an almost constant state of hypervigilance to threats, due to their histories of arrest, detention and abuse in authoritarian states. So news of this crackdown is certain to trigger “The mental health breakdown of many of the men, women and children who receive the care of our therapists.”
However, the plan could still be disrupted by court challenges.
Meanwhile, Mr Sunak said claims that the Rwanda plan is causing a surge in migrants to Ireland show it is already having a deterrent effect.
Earlier this week, Irish Deputy Prime Minister Micheal Martin said there had been an increase in the number of people crossing the border from Northern Ireland into the Republic, partly because people were “scared” to remain in the UK where they could be sent to Rwanda. .
In an interview on Sky News' Sunday Morning with Trevor Phillips, Sunak was asked about the comments and was challenged on whether the UK was simply exporting the problem.
The Prime Minister said: “My focus is on the UK and securing our borders.
“But what this comment makes clear is two things.
“Firstly, illegal immigration is a global challenge, which is why you see so many countries talking about third country partnerships, looking for new ways to solve this problem, and I think they will follow what the UK has led.
“But what it also shows, I think, is that the deterrent, according to your comment, is actually having an effect because people are worried about coming here and that says exactly what I'm saying.
“If people come to our country illegally, but they know they won’t be able to stay, they are unlikely to come, which is why the Rwanda scheme is so important.”
Taoiseach Simon Harris said Ireland “will not provide a loophole to the immigration challenges faced by anyone else.”
Justice Secretary Helen McEntee has been asked to introduce legislation to Cabinet this week to enable the return of asylum seekers to the UK.
But a British government source said on Sunday that it “will not accept any asylum returns from the European Union via Ireland until the European Union accepts the possibility of returning them to France.”
They said that the government is “fully focused on activating the Rwanda plan and will continue to work with the French to prevent boats from crossing the canal.”
More than 7,000 people have arrived on small boats so far this year.
Labour's Shadow Immigration Minister Stephen Kinnock said: “More people have arrived in small boats so far this year than ever before, and more people need to be rescued.”
“What will it take for Rishi Sunak to wake up and realize his plan isn't working?”
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