•A third of migrants as established by the report are migration related offences such as over- stayed visas, lack of work permits, lack of proper travel documentations etc.
•From the cost analysis this means Sh593,988,000 is a budgeted cost ripe for saving.
It costs the government approximately Sh2 billion annually to process migrants through the criminal justice system and repatriate them, a report has found.
The National Police Service uses Sh833 million, Immigration department Sh674 million, Judiciary Sh75 million and National prisons service Sh396 million.
The report by UNHCR on Monday, noted that the cost does not include processing costs for migrants who qualify for refugee status or asylum considerations.
A third of migrants as established by the report commit migration related offences such as overstayed visas, lack of work permits and lack of proper travel documentations.
From the cost analysis this means Sh593.98 million is a budgeted cost ripe for saving.
"Such savings can be achieved by deprioritizing the detention of immigrants without criminal records and moving those immigrants into alternatives to detention options," the report read.
Path followed by an irregular migrant upon arrest
This occurs at any border post in the country for a migration related offence such as procuring illegal entry into the country or for tampering their travel documents.
The migrant is then held within the immigration holding areas for a period of not more than 24 hours at an average of Sh2,000.
In cases where there is need for transportation to Nairobi, costs range between Sh50,000-90,000.
Judical processing of criminal case is Sh150,000, transporation to border court stations and upkeep Sh10,000.
Accommodation for victims of migrant related offences is between Sh3,000-5,000 per night.
The Kenya Prisons estimate the cost of maintaining a prisoner at Sh175 per day.
Imprisonment of three years translates to Sh191,625 and preparation of travel documents Sh10,000 per migrant.
Average cost of deportation per migrant is Sh100,000-150,000 per migrant. This includes security teams, air tickets and escort staff.
The study revealed that 32 per cent of the migrants in prison were detained for being in the country without proper documentation.
Sixty-six per cent of the migrants were detained due to other criminal charges ranging from human trafficking, drug trafficking, defilement, robbery with violence and fake passports among others while only two per cent were detained for being outside the designated area.
The majority of the migrant respondents were between the ages of 22-35 years with a 35% representation closely followed by respondents in the 36-60 years category at 32.5%.
It is evident that a majority of the migrants in detention are in the most productive age bracket of 22-60 years at 67.5% which is two thirds of the total number of migrants detained.
Forty per cent of the respondents had stayed in the country for about six months before they were arrested while 32 per cent of the migrants had arrived and remained in Kenya for more than five years.
Twenty of the respondents had been in Kenya for a period of less than one year while 17 per cent of the migrants indicated that they had stayed in Kenya for around three years.