The 34-year-old is sitting in a Hamburg jail cell after being arrested on suspicion of raping a young woman in a club toilet on Saturday evening.
But an admission by a local authority in Lower Saxony on Thursday has revealed that the man should have left Germany long ago.
After arriving in 2015, he made an asylum application in Holzminden, Lower Saxony. When it was rejected in April the man was told to leave the country by himself. Instead he vanished, turning up next in a Hamburg court after being caught pick-pocketing.
The Hamburg court handed down a probationary sentence and asked the authority in Holzminden to request the man be detained and then deported.
But on Thursday a spokeswoman for Holzminden said “we rejected doing this as we didn't have the staff to follow it through.”
Boris Pistorius, interior minister in Lower Saxony, reacted to the brewing scandal by saying: “why no arrest warrant was applied for, why no one reacted to Hamburg's request, these questions need to be answered.”
Deportations are often complicated by slowness on the part of the country to which a deportation should take place, often taking months or years until completion.
In Lower Saxony alone, several thousand people with deportation orders are still living in the state.
Hubert Meyer, chairman of the council of local administrations in Lower Saxony, said that there was “a huge amount of frustration” among civil servants on the length of time deportation cases take to conclude.
A fractious public debate has resurfaced in Germany over the past week on the relationship between asylum seekers and sexual assault, after two refugees were arrested last week on suspicion of rape.
In Freiburg in southern Germany, an Afghan, who says he is 17, is suspected of having raped and murdered a young student.
In that case too, administrative failings could well have contributed to a tragic crime.
On Thursday the German government confirmed that the suspect had already been jailed for attempted murder in Greece. But after serving two years of his sentence he was released and travelled on to Germany, despite the fact that this contravened the terms of his parole.
Greek authorities never alerted their counterparts in other European countries to the disappearance.
In the other case, an Iraqi man was arrested in Bochum last week on suspicion of rape and attempted rape of two Chinese students.
The debate first entered the mainstream of German discourse after hundreds of woman reported being sexually assaulted at New Year celebrations in Cologne last year by men described as being of North African appearance.
Critics of government asylum policies, which led to almost 900,000 asylum seekers arriving in Germany last year, say that letting in immigrants from Muslim majority countries increases the chances of sex crimes taking place in Germany.
Leader of the Alternative for Germany, Jörg Meuthen, said the crimes were the result of letting in young men from "Islamic-patriarchal cultures."
Government politicians, meanwhile, have accused critics of creating a climate in which all refugees are put under general suspicion.
Reported rape and sexual assault fell by 4.4 percent across Germany in 2015. Police have not yet released figures for 2016.