Details of the case were revealed this week when the now 18-year-old from Afghanistan appeared in court.
At the same time, it was revealed that after serving his sentence he will not be deported as the sentence is not more than three years, according to a report in the Kurier newspaper.
The pensioner, whose daughter Sylvia was a helper working with refugees, had been walking her dog alongside the canal in Traiskirchen, where Austria’s largest refugee centre is located.
She was attacked last autumn, but police admitted it was not reported at the time to local media because of the sensitivity of the subject.
The 72-year-old woman, identified only as Christina F., said: “It was a really hot day and I decided to take my dog for a walk along the Schwechat River, and saw two young men swimming there.”
Read more: Krone