Greenpeace on Friday warned that chemicals from a cruise ship wreck were oozing into the sea around Italy's picturesque Giglio Island, but the environment ministry said the levels were not "significant."
The organization, which conducted research on Giglio between February 15 and 18, also said it had detected traces of hydrocarbons in drinking water from a desalination plant on the island of around 82 micrograms per liter.
Researchers had found 2.12 mg per litre of ammonia in the sea, which could be due to "the decomposition of organic material" like food on the ship, and 4.35 mg per litre of material from soaps and industrial detergents.
The results are all below minimum reference levels in research carried out by the environment agency in the Tuscany region where Giglio is located.
"No significant pollution has been registered in the sea water," the environment ministry said in a statement, adding that traces of hydrocarbons and detergents were below levels that could be properly registered.
Local technicians on Giglio were quoted by ANSA news agency as saying: "There is no pollution alert for drinking water on the island."
"We have been carrying out daily tests on the sea water around the installation for more than a month and a half. All the results were well below the limits imposed by the law," the technicians were quoted as saying.
They suggested the hydrocarbons in the drinking water could have something to do "with the conditions of the plumbing and not the sea water."
Greenpeace Italy also called in its report for more action by the government to protect a marine sanctuary for dolphins and whales around Giglio.
"Greenpeace has been condemning the depopulation of the sanctuary, which has fewer and fewer cetacean species, as well as the multiple threats against a protected area that really exists only on paper," the group said.
"Why do we need disasters to think seriously about protecting the sea?"
It said it had warned many times about navigation in the area and the practice of cruise ships sailing too close to the shore, which has been blamed in part for causing the January 13 disaster in which 32 people were killed.
Dives carried out by the Greenpeace researchers around the wreck found that marine life and the condition of the sea floor were "good."