(ANSA) - Rome, November 20 - Italian judicial authorities on Tuesday ordered the preventative seizure of the Aquarius migrant-rescue ship in relation to a probe into the alleged illegal dumping of waste in which Medical-aid NGO Médecins Sans Frontières (MSF - Doctors Without Borders) is under investigation. The ship is currently in Marseilles.

The case regards the alleged dumping of dangerous and potentially infectious refuse, including medical materials, without the waste being separated, as if it were ordinary household waste.

Prosecutors suspect that 24,000 kilos of waste was dumped in this way on 44 different occasions.

The waste was alleged dumped in 11 ports - Trapani, Pozzallo, Augusta, Catania and Messina in Sicily; Vibo Valentia, Reggio Calabria and Corigliano Calabro in Calabria; Naples and Salerno in Campania; and Brindisi in Puglia.

In total, 14 people are under investigation in the probe conducted by State and finance police and coordinated by Catania prosecutors, sources said.

The authorities also requested the seizure of 460,000 euros.

"I was right to stop the NGOs' ships (landing in Italian ports)," Deputy Premier and Interior Minister Matteo Salvini said via Twitter.

"Not only did I stop the trafficking of migrants but, according to what has emerged, I stopped the trafficking of refuse too. #portichiusi (#portsclosed)".

MSF said that the Italian judicial authorities' request was a "disproportionate and unfounded measure, purely aimed at criminalising lifesaving medical-humanitarian action at sea". "After two years of defamatory and unfounded allegations of collusion with human traffickers, judicial investigations, and bureaucratic obstacles against our humanitarian work, we are now accused of organised crime aimed at illicit waste trafficking," said Karline Kleijer, MSF's head of emergencies.

The NGO said the in-port operations, including waste management, of its search-and-rescue vessels had always followed standard procedures.