Prosecutors in Puglia banned the culling of trees apparently affected with Xylella Fastidiosa, a bacteria with no known cure, accusing a task-force of university experts led by a governor-appointed commissioner of harming the environment.
The stop comes despite pressure from the European Union to fell the trees, with prosecutors arguing that "Europe was given a false interpretation of the Xylella situation... by regional institutions using inaccurate facts".
There was no proof of a clear link between the bacteria and symptoms of desiccation affecting thousands of trees in southern Italy, the prosecutors said, insisting further research was needed to prevent trees being wrongly axed.
"We have found trees not affected by desiccation which tested positive for Xylella and dried out trees which tested negative," Lecce prosecutor Cataldo Motta told journalists at a press conference.
He also said uprooting affected groves had not only failed to reduce the dry wood symptom, but that it was actually on the rise.
The ten accused, mostly teachers and researchers, are being investigated, among other things, for "spreading a plant disease" and "destruction or disfigurement of natural beauty" in the area surrounding Lecce from 2010 to today.
- 'Health risks, environmental damage' -
"From the moment the pathology of the desiccation of the olive trees appeared, without the cause being identified, a series of experiments were conducted using highly invasive products, prohibited by law, seriously compromising the environment, without any prior study of the impact," the prosecutors said in their written accusation.
The probe will look into the possible dangers to public health caused by the use of the pesticides and allegations of a conflict of interest over the products used.
Those accused include government-appointed project supervisor Giuseppe Silletti, staff at Italy's Plant Health Observatory, teachers at the University of Bari and researchers at the Mediterranean Agronomic Institute.
Silletti told journalists he had been acting "in defence of the countryside".
Puglia governor Michele Emiliano welcomed the investigation, as providing a basis to "challenge the European Union's strategy against Xylella, which is based essentially on the mass eradication of diseased and healthy trees".
The disease, which is not harmful to humans but can kill over 200 species of plants and poses a serious threat to Italy's olive and orange groves and vineyards, was first spotted in 2013 but the country was divided over how to tackle the threat.
Concerned over a potential spread of the bacteria to France or Spain, the EU urged Rome to destroy affected specimens -- a move that would potentially affect 10 percent of Puglia's 11 million or so olive trees, some of which are over a century old.
In October, Silletti finally ordered some 3,000 trees to be razed under an emergency decree.
But only 1,600 trees have been destroyed so far, with outraged olive farmers filing a flurry of appeals in Italian courts claiming that the order -- and a plantation ban -- have no scientific basis and could decimate the industry.