police in rhein erft , germany initially dismissed reports that a kangaroo was found hopping in a field in bruhl .
it was n't until the caller was questioned in detail and provided ` very believable ' answers , that the police realised that they were telling the truth .
they were shocked to find a large , australian kangaroo ` happily ' hopping through the town of bruhl , 20 kilometres south of the city centre of cologne .