Around 70 per cent of prisoners in Switzerland are not Swiss but not because foreigners commit more crimes according to a recent study.
Researchers at Bern University concluded that foreigners are seen as "flight risks" by authorities and are therefore more likely to be sent to prison than local criminals.
The report came as annual figures from the Federal Police Office showed the number of crimes, including those committed by foreigners, dropped in 2005 for the first time in five years.
The study by social scientists and legal experts said that since foreign men and women are generally sent back to their land of origin after serving their sentence, they therefore have a greater incentive to escape than Swiss criminals.
Because of this so-called flight risk, cantonal authorities lock them up in high-security institutions.
"Swiss prisoners on the other hand are increasingly serving their sentences in open prisons or are given alternative forms of punishment," Daniel Laubscher from the Federal Statistics Office told swissinfo.
Two-thirds of inmates in Swiss prisons do not have a residence permit and must leave Switzerland after doing their time – although serious offenders will in most cases be deported even if they have a residence permit.
As to why foreigners don't serve their sentences in their own countries, Laubscher said it is because of the time taken by the cross-border legal process.
"Prisoners will always start their sentences in Switzerland," he said. "But only those with long sentences will complete their sentences in their country of origin.
"Those with short sentences – predominantly people from abroad – have already served their sentence after three months."
The report did not see a reduction in the number of foreign prisoners in the near future.
However it did recommend various measures to prepare inmates better for life after prison, including the introduction of interpreters, reintegration programmes and the personalisation of how someone serves their sentence.
The number of crimes committed by foreigners last year was slightly lower than in 2004.
On Thursday the Federal Police Office reported that the number of reported crimes in Switzerland fell last year for the first time in five years.
A total of 303,270 crimes were reported, around 10.5 per cent lower than the previous year and matching 1995 levels.
"These statistics are dominated by break-ins – theft and burglary account for almost 80 per cent," said Laubscher.
"These crimes have dropped significantly – and as a result the total statistics have dropped – but that does not mean that other crimes are also going down. That's a quirk of statistics."
The greatest drop concerned theft (excluding vehicle thefts), which was down 13.9 per cent on the previous year; robbery, abduction and holding people against their will were also down around ten per cent.
There were 225 murders in Switzerland in 2005, a drop of 4.2 per cent.
Not all good
Not all trends were headed in the right direction. Money laundering and embezzlement were up, and reported cases of rape, coercion and threatening behaviour rose by 12.7 per cent to 646.
But domestic violence only became a crime in April 2004 and this reclassification would have had a significant effect on the statistics.
In addition, the number of drug-related deaths rose from 182 to 211. After a record year in 2004, the amount of cocaine seized in 2005 dropped to 283 kilogrammes.
Laubscher said the general figures were obviously to be welcomed, but he acknowledged that other more serious and often more violent crimes continued to increase.
"In principle it's good news, but with small changes for the worse," he concluded.
swissinfo, Thomas Stephens
Thorberg and Hindelbank were the two high-security jails in Bern used in the study by researchers at Bern University.
Thorberg houses male prisoners and Hindelbank female prisoners.
There are 45 nationalities at Thorberg and 25 at Hindelbank.
Since the beginning of the 1990s, 70 to 80 per cent of prisoners in Switzerland have been foreign – compared with 28 per cent currently in neighbouring Germany and 22 per cent in France.
According to the Federal Statistics Office:
The Swiss prison population topped 6,000 for the first time last year.
This represented a 15% increase on the previous year.
Of the 122 detention centres, around 40 were full and nine were overcrowded.
Champ-Dollon in Geneva has the highest average occupancy rate: 162% or 438 inmates for 270 places.