The news follows the arrest of the sculptor Anthony-Noel Kelly, 41, who was bailed on Wednesday, after police investigated the possible use of human remains to make plaster casts.
Dr Michael Hobbs, of Charing Cross Medical School, said: "With the best will in the world if someone is really determined to get round the security system then they can."
Bodies are made widely available for medical colleges. The Department of Health said about 800 people donate their bodies to medical science every year and it has granted licences to 39 institutions to use them for research and teaching.
Dr Hobbs, who is in charge of administering licences for medical institutes in London to obtain corpses for study, said: "We are extremely concerned this will deter people from donating their bodies. We don't want anyone getting the wrong idea."
Bodies were stored under tight security, he said. "Once we receive the body we allocate it an identification number and send it to one of the nine medical establishments in London. Only students, teachers and the relevant technicians are allowed access to them. Measures are taken to prevent visitors getting near the dissecting room.
"The bodies are used almost solely for teaching purposes and are used only in dissecting rooms. You can't just take bits of body from place to place. They are kept securely under lock and key. We even use extra grilles and bars on some doors to the rooms where the bodies are and some hospitals use CCTV. Another precaution is to not draw attention to the rooms where the bodies are kept - you won't find any signs directing you to them."
Dr Michael O'Higgins, of the Department of Anatomy and Developmental Biology at University College London Medical School, said: "This theft is an extremely rare occurrence. It is the first time I can remember this happening."
Despite the strict safeguards and the medical world's insistence on professional probity, tales of macabre misuse of bodies among medical students are legion.
One doctor, who graduated from the University of Birmingham Medical School and now works in the City, said: "There are lots of tall tales, but once students actually meet a cadaver they really are more respectful than flippant.
"When I was a student there were occasional reports of first years taking corpses for a walk down the centre of Birmingham. One student definitely took a corpse home on a bus ... He even paid the poor man's fare."
Meanwhile, Scotland Yard yesterday confirmed that a 24-year-old former employee of the Royal College of Surgeons had been arrested and bailed in connection with the removal of body parts earmarked for anatomical research.
A spokeswoman for the Royal College said that the person was a junior employee who had left the establishment "some years ago", but was not a surgeon.
Police were also reported to be examining body parts exhumed at Romden Castle in Kent, Mr Kelly's family seat near Ashford.
Both Mr Kelly and the former employee of the Royal College of Surgeons are being investigated under the 1994 Anatomy Act, which governs the use of human remains to train doctors and strictly forbids the use of body parts for anything other than medical research and study.
A Department of Health spokeswoman said: "We have no record of any bodies going amiss. We believe the medical schools look after them extremely well."
The procedure for donating a body follows a similar pattern to that for donating organs. Although many people donate their bodies for noble reasons, it is common knowledge among medical practitioners that many families chose the option as a means to ensure a free funeral.
Donors have to make a written or oral statement, in the presence of two people, that they wish their body to be used for anatomical research.
The health department spokeswoman said: "The next of kin, who legally own the body, are then approached. If there are no objections and no need for a post-mortem examination, the body is removed forthwith via an undertaker to the place of study.
"After the three-year period, the medical faculty using the body must approach the family and inform them that the time is up. The family can take the body and parts away for burial or they can leave it for the institution to organise."
The Royal College of Surgeons in London is home to a renowned anatomical museum and receives corpses from all over the country for biological research and study. Yesterday it declined to say whether it was reviewing security at its premises.Reuse content