To John Ward, Kenya is enemy territory, where Julie was murdered and the police did nothing to find her killers. At long last, however, Scotland Yard has taken an interest. Stephen Ward reports
Julie Ward was tortured and clubbed to death while on safari in a Kenyan game reserve seven years ago. Her body was found by her father, who flew out to look for her when she failed to catch her flight back to Britain. This week he is back in the news again, talking about the latest breakthrough in his personal crusade to discover the true facts of her death.

Over the past year, he has been interrogating a young Kenyan, Valentine Kodipo, who claims to have witnessed Julie's torture and murder. It has been an unpleasant experience, being face to face with a man who says he watched men kill and cut up his daughter. "When you hear the things he is saying happened to Julie, is it any wonder I keep trying to find the people who did it to her?"

This week it was revealed that Kodipo, a former secret police officer, had been interviewed by Scotland Yard detectives in Scandinavia in August.

Few causes would provoke a man in late middle age to fly over and over again to a Third World country he hates, to put his life in danger, to threaten the establishment and, seven years later, still be fighting, still be flying thousands of miles a year.

Julie Ward's brutal death at the age of 28 has been enough to inspire her father to do all that. John Ward, now 63, disliked Kenya even on his first visit, when his daughter was still only missing. For all the friends and allies he has made in almost 50 visits since then, he still hates the land his daughter fell in love with, and would be happy never to see it again. But he is prepared to do almost anything if it brings him closer to knowing exactly how she died, and to bring her killers to account.

Over the years, he has written a book. Now this story may be made into a film - showing how he hired detectives, cars, planes, forensic scientists and lawyers; how he forced the Kenyan authorities to admit they had covered up her murder to make it look as though she had been killed by wild animals; how he had to sleep in a hotel room with his daughter's skull in a carrier bag in the corner, how he forced the police to bring two people to trial, how they were cleared, and how the police have so far failed to act on the judge's recommendation that they consider the case against three other named suspects.

That makes him sound obsessive, a label often used about parents who have lost children by people who have not. Campaigners about cot deaths and meningitis have faced the same accusation. Mr Ward has heard the description applied to himself. "I never really accepted it," he says, thinking carefully, "because ... for instance ... if all the evidence was that she had been killed by animals, and I had this bee in my bonnet that there was more than that, then that would be obsessive because I would be flying in the face of the facts. But all I'm doing is following evidence and trying to evaluate the facts as I know them to be."

He misses Julie a great deal, but admits it is worse for his wife, who spent more time with her as she was growing up. Mrs Ward has remained at home while he sought their daughter's killers, as she did while he was working long hours to build up his businesses, although when she finally visited Kenya for the trial, she fell in love with the country the way that Julie had.

Cynics sometimes suggest campaigners even grow to enjoy the publicity. They miss the point that Mr Ward has learnt to use media coverage as a shield in a country where people disappear all the time with few questions asked, that he knows how it operates - with anything but enjoyment. Asked how the years have affected his family - his wife, Jan, and Julie's two younger brothers - he says: "Things can never be the same. Our previous, private, existence has disappeared; constant media exposure has seen to that. But it is a price we willingly pay. The media have always sought to expose the truth behind Julie's murder. If you lot hadn't been sitting in court in Nairobi, we wouldn't have got the murder verdict."

His objective has always been limited - to find out how Julie died - but the effects on Kenya have been remarkably wide-reaching. He is not exaggerating when he says: "I think it's had an effect, certainly, on tourism, and an effect, therefore, on the economy. Certainly it's true the name Julie Ward is known throughout Kenya. Talk to anybody; they all know about the case and they all know it stinks. The population knows the government and the police were involved in a cover-up."

The ramifications of the case go beyond that. John Ward was never an innocent abroad, but nothing in his career building small hotel chains in the Home Counties prepared him for the political and diplomatic context he was ploughing into.

The Kenyan police wore uniforms like the Suffolk police, and they spoke English. Nairobi seemed like an English town. Mr Ward expected that if there were a missing tourist, they would look for her, and if there were a body, they would look for the killers. But the police took no interest at any level, as they routinely took no interest in many killings. In fact, they began to show an interest only when the damage to tourism caused by the fuss Mr Ward was making appeared greater than if they were to admit a murder had taken place in the Masai Mara game reserve.

He had expected support from the Foreign Office. Local officials helped, but in Whitehall and Westminster, as he quickly discovered, there was a different priority, a desire to keep our only good friend in Africa.

He is on first-name terms with British Cabinet ministers who keep an eye on the case. He has even met President Moi, to ask him for compensation. The president suggested an ex-gratia payment, but would make it only to the British Government. The Law Officers advised that the Government could not get involved in such bargaining, so if Mr Ward wants his money, he will have to sue in a Kenyan court.

The pounds 500,000 or so he has spent would have bankrupted many men. He has managed to continue his business through a recession despite the interruptions. But he is now at the point where he has to sell either shares in his hotels or his large, modern home in Suffolk. "When Julie was murdered in 1988, I considered we were fairly comfortably off. Not rich - all this millionaire stuff is nonsense - but we were secure. All that has changed. It's a big house and there's only two of us now. I shall be sad because I've worked hard on the house. But there's a price to be paid for these things."