More than 8,000 migrants crossed the Channel to the UK in August – the highest monthly total on record.
Some 8,644 made the crossing on 189 boats in the 31-day period, with journeys taking place on 21 of those days, according to PA news agency analysis of government figures.
It is the highest monthly total since current records began in 2018.
Previously, it was 6,971, recorded in November 2021.
Meanwhile, the National Crime Agency said it is running about 60 investigations into suspects using small boats to smuggle thousands of people into the UK.
August 22 saw the highest daily total on record, with 1,295 people crossing in 27 boats.
More than 25,000 people have made the crossing in 2022 so far, according to official Home Office figures and provisional data collected by the Ministry of Defence.
Last week, Home Secretary Priti Patel struck a deal with the Albanian government to step up police activity and fast-track removals in a bid to tackle crossings after numbers increased “substantially” over the last few months.
Up to 60% of arrivals are now thought to be from the south-eastern European country.
The Home Office said one of the people returned on Thursday’s flight to Albania was removed 24 days after “entering the UK illegally” by crossing the Channel on a migrant boat last month.
Others included someone who was removed 19 days after being caught by immigration officers working in a restaurant, having overstayed as a visitor, and another who arrived hidden in a lorry in May.
Among the foreign criminals were those convicted of supplying class A drugs, facilitating illegal entry and sexual offences.
It is more than four months since Ms Patel unveiled plans to send migrants to Rwanda in a bid to deter people from crossing the Channel.
Since then, 19,775 people have arrived in the UK after making the trip.
On April 14, Ms Patel signed what she described as a “world-first” agreement with Rwanda, but the first deportation flight – due to take off on June 14 – was grounded amid legal challenges.
Several asylum seekers, the Public and Commercial Services union and charities Care4Calais, Detention Action and Asylum Aid are challenging the legality of the Home Office policy, with the next court hearings due to take place from Monday.
Campaigners called on the Government to abandon the plan and free those awaiting removal from detention.
Medical Justice said torture and trafficking victims are among those told they could be sent to the east African nation, according to assessments by its doctors.
The charity argued the health and wellbeing of the detainees has been “severely” affected by the policy and, for some, it has “increased their risk of self-harm and suicide”.
The Home Office disputed the findings and insisted “no-one will be relocated if it is unsafe or inappropriate for them, and our thorough assessment of Rwanda has found that it is a fundamentally safe and secure country, with a track record of supporting asylum seekers”.