Mr Puttock had endoscopes valued at £80,000 at cost taken when thieves broke in his factory around four weeks ago.
Now his insurance company has offered a reward for information leading to the return of the stolen items and the arrest and conviction of the thief or thieves.
"I have no criticism of the two police officers who arrived at the scene or the scenes of crime officers, but I am annoyed and upset that there has been no investigation by CID officers," he said.
"There were clues. There was a very plain footprint and a lead through items dumped in a skip in our yard around the same time, but we have since been told that the investigation has closed.
"I have tried to speak to a police officer locally to put in a complaint but it has just not been possible. I have simply been unable to speak to a senior officer," he said.
Mr Puttock said there was information which he believed the police could have followed up.
"I feel badly let down. The endoscopes are numbered and of no value outside the medical profession. They have probably been dumped somewhere locally," he said.
In a statement police said on Tuesday: "A number of enquiries have been made and Scenes of Crime Officers attended to take forensic evidence, which mayhave been left at the time of the crime.
"The Gloucestershire Constabulary has to have reasonable grounds of suspicion before an arrest can be made. Without that evidence, and without being able to obtain the necessary evidence, we are not in a position to affect an arrest.
"We have exhausted all avenues of enquiry on this crime, however should further information come to light the case will be re-opened."