THE idea of a beetle moving around inside your body may be the stuff of horror films.

But scientists believe an insect-shaped robot could be a major weapon in the fight against cancer.

The device, just under an inch long, is designed to be inserted into the body through a small incision.

Once inside, doctors can control its movements and direct it to areas where investigations are needed.

It would be able to capture images through a tiny camera placed in its 'head' and could deliver drugs through a special injecting device.

Early versions have also included tiny forceps for taking tissue samples. In future these nippers could be used to snip out cancerous cells.

Less than half an inch across, the metal device is encased in plastic to protect its components while in the body. It is connected to a computer by a cable through which it relays data and images.

This can also be used as a 'safety line' if the beetle goes off course.

Doctors would be armed with MRI body scans of the patient taken in advance to help them navigate the robot.

However, unlike the plot of the 1966 Raquel Welch film Fantastic Voyage which featured a microscopic crew and submarine travelling through a scientist's bloodstream this device could not be inserted into blood vessels because it is too big.

But it could be placed within the digestive tract, where it could be used to seek out and treat cancers of the oesophagus or bowel.

In tests on animals the robot, which weighs around five grams and is roughly the size of a cockroach, is said to have performed very well.

The prototype, which is the result of three years' work by researchers at Ritsumeikan University and the Shiga University of Medical Science in Japan, was unveiled yesterday.

It is not the first time that scientists have developed mini- robots to work inside the body. Other researchers have created ones which are designed to be swallowed and take internal pictures. And U.S. scientists are working on a small robot that enters though an incision to treat heart problems.

However, the latest model is the most versatile and able to perform the most functions.

According to one of its developers, Professor Masaaki Makikawa, this new prototype robot has the ability to perform treatment inside the body, eliminating the need for surgery in some cases.

Miniature robots able to move through the body would be particularly useful to investigate and treat tumours in hard-to- reach parts of the body, such as sections of the bowel.

In 2005, New Scientist magazine reported that Italian researchers were developing a six-legged robotic camera that crawls around inside the body and attaches itself to the intestine wall.

Its legs had tiny hooks on the end so it could crawl through the gut without slipping. It also had a special clamp that allowed doctors to stop it altogether if they spotted something of concern and needed to take a closer look.

At the time, researcher Dr Ariana Menciassi, of the Sant' Anna School of Advanced Studies in Pisa, said: 'All the indications are that this will be far less uncomfortable than a colonoscopy or gastroscopy in which the intestine is inflated, causing much pain to the patient.'

j.wheldon@dailymail.co.uk

THE BEETLE ON A MISSION TO HEAL

The tiny robot is inserted through an incision into the body.

The doctor is then able to control its movements and direction.

The device is capable of capturing images through a tiny camera placed in its 'head' and deliver drugs through a special injecting system.

Length: 2cm Weight: 5 grams Encased in plastic for protection

Forceps Camera take tissue samples

Encased in plastic for protection

2mm cable relays information and also used to retrieve device