Berlin  - A German teenager who left a Halloween joke alien in a glass jar on the counter of an ice cream vendor was surprised Thursday at the uproar his prank caused when he heard reports on local radio.

On being called by the sales lady, police took the plastic alien to pathologists for checking.

Initially the experts said the object could be a human foetus showing signs of deformity, but a forensic expert, on taking a scalpel to it, revealed it to be made of plastic.

The 16-year-old, who had placed a teabag in the jar to enhance the effect, phoned the authorities to own up after hearing the radio reports.(dpa)