The number of prisoners in Switzerland has soared in the last 30 years with foreigners now accounting for 80 per cent of the prison population, according to the Swiss Federal Statistical Office.

The study shows the rate of incarceration has gone from 72 per 100,000 residents in 1988 to 82 in 2017, Radio Télévision Suisse reports.

During the 30-year period, Switzerland saw its prison population increase from 4,621 to 6,907, a 50 per cent increase overall.

In the first decade from 1988 to 1998, Swiss citizens made up around 31 per cent of the prisoners compared to 28 per cent who were foreigners living in Switzerland and 41 per cent who were foreigners residing overseas. In 1989, Swiss citizens made up as much as 44 per cent of prisoners.

During the next two decades, the number of Swiss citizen prisoners fell to only 20 per cent, with foreigners residing in Switzerland going up to 37 per cent in the second decade and back down to 28 per cent in the third.

Foreign prisoners who live overseas rapidly grew in the third decade to where they now account for over half of the prisoners in the Swiss prison system.

The deportations make up only a fraction of the total number of foreign adults convicted of misdemeanours or felonies in Switzerland. https://t.co/DX33u9KVeN — Breitbart London (@BreitbartLondon) October 11, 2018

The statistics come only months after it was revealed that Switzerland had deported 1,000 migrant criminals in 2017, including 348 from the Balkan region and 250 from Africa.

The trend also mirrors other European countries which have seen high rates of crime in which foreign nationals are often suspects.

In Germany, certain cities such as Berlin have released statistics showing that up to half of the crimes committed in the city involve foreign suspects. In some specific crimes, foreigners were shown to be vastly overrepresented including heroin trafficking where migrants made up 85 per cent of suspects in 2016 in the German capital.

In the Austrian capital of Vienna, the disparity between the crime rate of natives and migrants is even starker with foreigners making up more than half of all the suspects in crimes, according to a report released last August.