Norman McMullan, 61, became known as Karl Frankfurt after he turned up in Mannheim with no memory of his name or where he came from.
He was looked after at a home where he quickly became very popular among staff and other residents, despite knowing nothing about who he was.
Once his identity was established, authorities began making plans to extradite him from Germany to the UK, despite his pleas to stay where he was.
The German authorities said they would not pay for his care, though caretakers also asked that he be allowed to stay.
He disappeared in early December, shortly before he was due to be sent to the UK.
Now he has been found in Switzerland, where he is being treated in a psychiatric hospital in Zurich – under the name Norman Switzerland.
His legal representative Wolfgang Wagner said his client, who he says suffers from paranoid schizophrenia, is doing well.
He said it would seem McMullan had gone to Switzerland by hitch-hiking or by train.
The Swiss authorities must now decide what to do with him.