Hugh Ind told the Home Affairs Select Committee there had been occasions where individuals had been brought back to Britain following wrongful removal.
Asked by MPs to give a precise figure, the Home Office’s most senior immigration enforcement official said it was “up to five”.
This came a matter of minutes after immigration minister Caroline Nokes said she was not aware of any cases.
But Labour MP Stephen Doughty then raised the case of one of his constituents, who was wrongly deported to Somalia.
A difficult afternoon for Caroline Nokes in front of @CommonsHomeAffs.
When asked why she had not been briefed about the number of wrongful detentions and deportations upon taking office, she tells MPs: “I don’t think I can answer that.”
— Alan McGuinness (@Alan_McGuinness) May 8, 2018
He asked Ms Nokes why she had not been briefed about the number of wrongful detentions and deportations in her department upon taking office.
“I don’t think I can answer that,” the minister responded.
Mr Ind, director general of immigration enforcement, acknowledged during his evidence that there is a “deep problem” with wrongful immigration detentions.
He told the committee that about £3.3m was paid out last year in compensation for detentions later ruled unlawful in the courts.
On the Windrush scandal, MPs were told officials are reviewing 8,000 records stretching back to 2002. So far, no wrongful removals have been identified.
However, Ms Nokes said it was clear that people from the Windrush group have been detained.
The scandal set in motion a chain of events that resulted in the resignation of Amber Rudd as home secretary.
Ms Rudd quit after admitting “inadvertently” misleading MPs about targets for removing illegal immigrants.
During questions from the Home Affairs Committee, she told MPs there were no such targets. But following a string of damaging revelations contradicting her evidence, Ms Rudd stepped down.
The Home Office’s top official revealed to the committee that an urgent review is taking place into the “support” given to Ms Rudd prior to, during and after her session on 25 April.
Sir Philip Rutnam, the department’s permanent secretary, said: “There is a lot of concern about the preparation for the hearing, concern about events during the hearing and after the hearing.
“My concern is to make sure the quality of the advice and support we are giving to our ministers is as good as it possibly can be.”
Sir Philip said he had asked Sir Alex Allan, a top civil servant who is currently the Prime Minister’s adviser on ministers’ interests, to look into “the facts so far as the support provided by the Civil Service”.
Sir Philip said: “That is a piece of work which is being started today and which I hope will be concluded quickly.
“I hope that provides you with some reassurance that I take these matters very seriously.”
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On the subject of targets, Mr Ind confirmed a target was set for enforced returns of 12,800 for 2017/18, while there were also targets in 2016/17 and 2015/16.
He said it was decided not to operate targets for returns in this year.