An Oxford University researcher whose pictures of a beating rat's heart have been applauded in a national competition has highlighted the importance of animal research.

The scientist, from the department of physiology, anatomy and genetics, wants people to understand that much of the work done within the city is non-invasive and that many studies involving games and exercise are enjoyed by animals.

But although he believes his studies are essential to help develop vital treatments and therapies, he is still forced to stay anonymous for fear of reprisals from animal rights activists in another example of the fear caused by the campaign against the university's new animal testing laboratory.

The university has come under fire from protestors because of the £20m research lab it is building in South Parks Road.

Two bombs were found at Templeton College in Kennington on Monday.

Many researchers, lecturers and companies linked to the new lab have been targeted by arson and vandalism attacks and threats by animal rights activists.

The scientist uses rats to further stem cell research, and his illustrations show one animal's beating heart taken with a magnetic resonance imaging scanner (MRI).

The images, tracking a single heart beat lasting just one seventh of a second, were chosen as runner-up in the British Heart Foundation Reflection of Research contest.

He said: "Our research is not invasive. The animal is under general anaesthetic but recovers in a matter of minutes. We monitor them very carefully and they're perfectly happy after the experiment. The end product is stem cell therapy.

"The animals enjoy the studies we do. We give them exercise and we play with them, to monitor their behaviour.

"Using MRI is a very good method because we can do it multiple times and it's very accurate, which means we don't have to use as many animals in our research because the margin of error is smaller."

The scientist's own work concentrates on looking at treatments to repair failing hearts using adult stem cells.

Stem cells harvested from bone marrow are injected into the heart, helping replace the dead and damaged tissue with regrowth.

He admitted some rats were killed to harvest the bone marrow, but most of those used were fit and healthy, and the only invasive work on them was a final dissection at the end of their lives.

He added: "It's absolutely essential scientists can do this. It's actually very difficult to get permission and there are stringent rules.

"Not only does the department have to apply for a licence, but each individual has to be licensed too. And we can't just decide to do something on the spur of the moment.

"We have to apply to the Home Office for everything we do with the animals."

But Robert Cogswell, of anti-vivisection group Speak, accused the scientist of anthropomorphism - treating animals like humans.

He said: "How can you say a rat is enjoying something unless you can get inside its head?

"The fact is this rat is being caged and ultimately killed by a vivisectionist.

"We have to look at what vivisectionists are saying, and what the truth is, and until there is an independent scientific evaluation of vivisection this can't be done.

"It's not as simple as saying it's one rat to save millions of people. Millions of animals have already died and we're still no closer to finding cures for many illnesses."