Mr Hart, who runs a marketing services company, asked his friend Allistair Mitchell to help him investigate the dragon's background.
Mr Mitchell, 42, who runs a marketing company in Oxford, said: 'The late 1800s were a time of intense rivalry between Britain, Germany and France over who was the world's leading nation.
'It would appear that this was an effort on the part of interested parties in Germany to discredit the British scientific community.
'At the time, scientists were the equivalent of today's pop stars and their achievements were heavily reported in newspapers.
'It would have been a great propaganda coup for the Germans if it had come off. Some of the documents are in German and date back to the 1890s.
'I've shown the photos of the dragon to someone from Oxford University and, like everyone who sees it for the first time, he thought it was amazing.
Obviously he could not say if it was real or not but he wanted to come and take a biopsy of it.
'It is a truly amazing thing. It stands about 30 centimetres but if you were to take it out of the jar and lie it flat with the tail extended, it's probably about a metre long.
'The dragon is flawless, from the tiny teeth to the umbilical cord. No matter how closely you look, you cannot tell if it is real.
It could be made from India rubber, because Germany was the world's leading manufacturer of it at the time, or it could be made of wax.