The Iranian national was detained and the Government intends to send him back to France again after he crossed the Channel a second time, it is understood.
Children’s minister Josh MacAlister said it shows the Government’s one-in, one-out migrant returns deal with France is working.
He told Times Radio: “I think it shows the scheme working, because this guy came here. He shouldn’t have come here. He paid somebody, a smuggling gang, to cross the Channel.
“He was stopped, he was detained, and he was returned to France. He came again. He paid someone again, and he will be returned to France again.”
This sends a clear message to those who cross the Channel in small boats that “you will be deported”, Mr MacAlister said.
“You will go back to France. The money you’ve spent will be wasted. And if you do it again and again, you will be returned again and again.”
The minister could not say whether the man would be counted once or twice on the returns statistics.
The man who came back to the UK on October 18, after being sent to France on September 19, told the Guardian he was a victim of modern slavery at the hands of smugglers in the north of the country.
Mr MacAlister called this a “ludicrous claim”, and stressed that “France is a safe country”.
Details of the man’s re-entry emerged as it the number of small boat arrivals for the year passed the total for 2024.
The number of migrants who have come to the UK so far this year in small boats has exceeded the total of 36,816 for the whole of last year, latest Home Office figures show.
Some 220 people made the journey in three boats on Wednesday, bringing the cumulative total for the year so far to 36,954.
The “one in, one out” deal struck between Sir Keir Starmer and French president Emmanuel Macron earlier this year is aimed at deterring small boat crossings by enabling deportations of anyone deemed not to have a right to stay in Britain.
The treaty means people who arrive in the UK by small boat can be detained and returned to France, in exchange for an equivalent number of people who applied through a safe and legal route.
France had also been expected to change the way it patrolled its waters to intercept the boats, but the BBC has reported that the country is backing away from that commitment, citing French sources.
Home Secretary Shabana Mahmood also faced pressure over a secret report – written during the previous Tory administration – that found a “culture of defeatism” within the Home Office.
Ms Mahmood conceded the Home Office is “not yet fit for purpose” but said her department had been “set up to fail” in response to the release of a highly critical review by former Home Office special adviser and Tory whip Nick Timothy.
The Home Office sought to keep the report secret for more than two years before it was obtained by The Times following a legal challenge by the newspaper.
It warned of “several confused and conflicting systems working to contradictory ends” resulting in “poor” enforcement of immigration laws, as well as a “culture of defeatism” on immigration.
Mr Timothy found that the “hand-offs between immigration enforcement and other parts of the immigration system are poor, as are the hand-offs with the police and criminal justice system”.
Ms Mahmood said on Wednesday: “This report, written under the last government, is damning. To those who have encountered the Home Office in recent years, the revelations are all too familiar.
“The Home Office is not yet fit for purpose, and has been set up for failure. As this report shows, the last Conservative government knew this, but failed to do anything about it.
“Things are now changing. I will work, with the new permanent secretary, to transform the Home Office so that it delivers for this country.”
Dave Penman, general secretary of the FDA Union of civil servants, defended Home Office staff.
“If you’re working in the Home Office, and you’ve seen failed policy after failed policy after failed policy, is there any surprise you’re going to feel a little bit defeated?” he told Times Radio.
Mr Penman said they “try to implement” policies, but that “you can’t tell them they have to believe in something that when they look at the evidence in front of them isn’t going to work”.
