In a tranquil English field, we find the Government's secret GM crop

The photograph on the right shows genetically modified maize, growing in a Shropshire field. We know where it is, but we can't tell you.

The photograph on the right shows genetically modified maize, growing in a Shropshire field. We know where it is, but we can't tell you.

The farmer says he has nothing to hide, but is worried for his own safety. We have chosen to respect his wish for anonymity, in order not to make him a scapegoat. Public accountability is the main issue at stake, rather than the actions of any one farmer.

The Government has repeatedly sworn to be open about GM trials - but still it refuses to reveal the location of this and at least four other experimental crops across England.

And it is fighting a proposed European law which would force it to put the sites of these experiments - and any future commercial GM crops - on a public register.

"There is no doubt that there is potential for harm, both in terms of human safety and in the diversity of our environment, from GM foods and crops," wrote the Prime Minister in this newspaper last February (see above). "The protection of the public and the environment is, and will remain, the Government's over-riding priority."

The environment minister, Michael Meacher, ordered map references to be published so that neighbouring farmers and protesters alike would know the locations of 25 farm-scale trials being carried out into the safety of GM crops.

But last Sunday we revealed the existence of a new - secret - clutch of GM trials in fields across England, authorised by the agriculture minister Nick Brown. Not even Mr Meacher knew where they were. Mr Brown was under no obligation to tell him.

On Monday the ministry revealed the parishes in which the experiments were being held to Friends of the Earth. They were Shirburn in Oxfordshire, Brockley in Somerset, Bramham-cum-Oglethorpe in North Yorkshire, Histon in Cambridge- shire and Rowton in Shropshire. But officials still would not give exact locations.

The Independent on Sunday set off to find the one which was said to be in "the parish of Rowton", in the quiet countryside near Telford. In fact no such civil parish exists, and the farm in question does not even fall within the boundaries served by Rowton parish church.

The small square of 8ft-high maize is an eerie and unexpected sight, rising from the centre of an otherwise uncultivated 30-acre field, on the side of a shallow valley. The crop is enclosed by a low electric fence, to keep rabbits out.

On Friday the farmer - we shall have to call him Mr G - said he had been "led to believe" that the trial taking place in his bottom field was on a register, and therefore public knowledge. No protesters came near the farm after the crop was planted in March, so Mr G assumed he was safe. But when the new list of secret trials was published, campaign groups began searching all over the county for the site. They have yet to find it.

Most of the 500 maize plants in the field are conventional, but about a tenth have grown from seeds genetically modified by the Franco-German company Aventis to withstand herbicides.

This GM maize is the same as that destroyed by Lord Melchett and 27 other activists who were acquitted by a jury in September, and is the subject of a current public hearing into whether it should be grown in Britain at all.

The crop in Mr G's field was planted by staff from Harper Adams College in Newport, Shropshire. At first Charles Murray, of the agriculture department there, denied the college had any involvement with GM testing. However, when pressed he said: "I can't tell you about it. It's not my job to. The whole thing is very secret." The college has grown and monitored the crop for the National Institute for Agricultural Botany, which is itself under contract to the Ministry of Agriculture, Fisheries and Food.

The office from which Mr G runs his farm is difficult to find in the maze of country lanes between villages. The business established by his father now employs 120 people, with a turnover of £12m-£15m. The dairy herd was sold years ago, the pigs have gone, and the sheep will follow by the end of this year. The family makes its money by managing farmland for absent owners, using it for the large-scale production of eggs, cereals and potatoes for crisp manufacturers.

When the college approached Mr G in March there was much talk of farmers feeling too intimidated to offer trial sites, for fear of protesters. "It was a worry," he said on Friday. "But at the end of the day you have to have conviction. You can't just stand still. If someone's playing around in the lab, at some point you have to have field trials. To humanise it, at the moment people are having flu jabs - but who were the first guinea pigs for those? Someone has to do it. You have to trust good science."

The most he would earn from the trial was £72, he said, as compensation for the payment that would have been due if the land - less than an acre - had been set aside. "It's important to stress that, because people think we're getting up to £15,000."

He took the trial on out of principle, because the potential for GM crops being used for good was "colossal".

The maize would be harvested in the next fortnight, he said. "All they've told me is that they're taking it away, evaluating it, and the whole crop is destroyed at the end so there's nothing left on the farm."

The farmer was advised to put safety first in the event of a protest. "They've left me a couple of telephone numbers to ring if a whole load of people turn up in white suits, but they've quietly suggested that I don't put my family or my staff in jeopardy."

Mr G said he would not have agreed to the trial if any of his neighbours had been growing maize, or feeding their dairy cows on it. Likewise, he had decided against growing GM oil-seed rape because they farmed the ordinary version.

"Since all this media hype was drummed up I have been told that one of my neighbours is starting to go organic," he said. "I believe he is something like six miles, 20 or 30 fields, three roads and a village and a half away."

Mr G insisted he had not known the trial was secret. "In the early stages I was led to believe that it was on a website somewhere. I believed I was on a national register."

Safety had now become a worry. "I have discussed it with my wife this morning. I'm not at home very much, like a lot of farmers this time of year, out in the fields. It is concerning not to know what you're going to be confronted with, and what some of these extremist youths and people actually do."

"If you could find me then I'm sure a lot of other people could."

Last night, Tim Yeo, the shadow agriculture minister, said that the Independent on Sunday's rapid discovery of the site showed it was "ridiculous to keep the trials secret". He said he was now calling for all five locations to be made public.

He added: "If ministers want to have any serious chance of getting this technology accepted, they have got to act in a more open and honest way."

But the Government is resisting a new European measure that would force it to be open about all its GM sites.