One of Europe's largest suppliers of fruit and vegetables is being investigated for alleged environmental crimes in Spain, according to an exclusive report by German public broadcaster ARD.



The company reportedly supplies Germany's largest supermarkets, including Rewe, Edeka, Lidl and Aldi Süd.



Read more: Wastewater crop irrigation risks health of nearly a billion people

Details of the allegations

The public prosecutor's office in Murcia told ARD's "Report Mainz" that:

About 40 farmers, officials and agricultural companies are suspected of using illegal methods to pump water and purify it in unauthorized desalination plants.

One of those companies was allegedly G's Espana, which supplies major German grocery chains.

It allegedly used hidden pipes to dump highly concentrated nitrate-containing wastewater and other environmental toxins into the Mar Menor lagoon or soil.

The dumping caused serious damage to the flora and fauna in the lagoon.

The "serious crimes against the environment" are punishable with five years in prison.

Read more: The true cost of Germany's cheap food

Feeding the world of the future: is hydroponics the answer? Tackling food insecurity with hydroponics The challenge of feeding a planet that’s set to have 3 billion more people on it by 2050 - made even more acute by climate change as some parts of the planet become wetter, while others drier - means the pressure is on to find ways to feed the planet. So farming has to become more productive – and new areas to grow, especially in dry climates, must be found. One potential solution: hydroponics.

Feeding the world of the future: is hydroponics the answer? Growing plants in the air Farming with little space and producing higher crop yields: hydroponics fits the bill. Though it may sound like something out of Star Trek, it's actually been around since the Aztecs – they built floating farms around the city of Tenochtitlan. Hydroponics essentially means growing plants without soil, and instead using a nutrient-rich solution to supply them with water and minerals.

Feeding the world of the future: is hydroponics the answer? Boosting yields With hydroponics, plants – usually supported by soil – are propped up artificially instead, and a nutrient solution is applied to the suspended roots using a number of different methods, including spraying them with a solution mist. Together with artificial lights, heaters and other equipment, the nutrient solutions help plants develop faster, produce larger yields and grow all year round.

Feeding the world of the future: is hydroponics the answer? Efficient hydroponics Hydroponics can recycle water, meaning it could use as little as 10 percent of the water a conventional farm uses – making it an option in arid environments. And the closed system means nutrients don't escape, cutting fertilizer down to as much as a quarter of what a conventional farm would use. Also, almost no pesticide is needed, since soil pests aren't an issue for plants grown without soil.

Feeding the world of the future: is hydroponics the answer? Planting vertically When growing sideways isn't an option, try going upwards: hydroponic growing trays can be piled on top of one another, and plants can be grown more closely next to each than in the soil, making it very efficient in terms of space. As for what kind of space they can grow in, the sky is the limit: with no need for scarce farmland, one possibility could be to have hydroponic farms in skyscrapers.

Feeding the world of the future: is hydroponics the answer? The downsides of hydroponics Running a hydroponic farm can be complex, energy-intensive and expensive. Plants require many essential nutrients, and the farm needs a large amount of equipment. Heat and light, supplied for free by the sun in conventional farms, have to be provided artifically and paid for. And power failures could mean whole crops are destroyed if they go too long without water and light.

Feeding the world of the future: is hydroponics the answer? Hydroponics on the rise Hydroponics can theoretically be used to grow any crop, although the technique lends itself best to plants such as cucumbers, salad greens, tomatoes, peppers and herbs. Given its long history, hydroponics still isn't widely used. But that looks set to change: the global hydroponic farming industry was estimated to be worth $21.2 billion in 2016. That's forecast to grow by 7 per cent each year. Author: Melanie Hall



Supermarkets hand responsibility to certification groups

Although Rewe did not respond, Edeka, Lidl and Aldi-Süd told the broadcaster they relied on environmental certification companies to ensure environmental regulations are followed. Aldi-Süd said it had initiated an ad hoc audit of the company and would investigate the certification checked. G's Espana itself did not respond.

Environmental damage: Mar Menor is the largest lagoon in Spain and has international environmental significance. Parts of the lake, including extensive salt flats, are protected at various levels. But in 2016 pollution levels bought the area close to ecological collapse. Environmental changes led to enormous changes in the ecosystems, with many important plant and fish species disappearing entirely.

Read more: Five of the world's biggest environmental problems

The company: G's Espana is the Spanish subsidiary of the British G's Group. A cached version of the Spanish website, which was down at the time of writing, said they control 5,000 hectares (12,355 acres) of farmland in Spain and 12,500 hectares around the world. The group boasts of promoting sustainability throughout the supply chain and working in an ethical and responsible manner.

Germany to blame? Germany enjoys notoriously cheap groceries in its supermarkets and this has been blamed for placing pressures on farmers to cut their costs. Campaigners have pressured the German government to ensure hidden costs, such as filtering nitrates out of drinking water, are included in the final checkout price.