The helicopter had taken off on Thursday from Lucca in Tuscany and was heading towards the northern city of Treviso when it was lost in bad weather over a remote area.

"The rescuers have found dead the seven passengers from the helicopter, four of Turkish and two of Lebanese nationality, who were on a business trip to Italy. As well as the Italian pilot," the prefect's office in the city of Modena said in a statement.

The helicopter was found in a mountainous area on the border between Tuscany and the Emilia Romagna region, the statement said.

Prosecutors have cordoned off the area as part of the investigation into the incident.

"We got the coordinates, we went to the site and found everything burnt. The helicopter is basically inside a valley, near a stream," a rescuer said in a video posted on the Italian Air Force Twitter account.

The Turkish businessmen worked for Eczacibasi Consumer Products, a subsidiary of major Turkish industrial group Eczacibasi. They had been attending a paper technologies fair in Italy, the company said in a statement.

The helicopter was an AW119 Koala manufactured by defence group Leonardo, a person close to the matter told Reuters.

The ANSA news agency reported it was owned by transport and aeronautic maintenance company Avio Helicopters, based in Thiene, in northern Italy.