Two people have died in an explosion while driving a prototype car during a trial to find a way of turning combustible engine vehicles into solar-powered ones.
Researcher Maria Prati, 66, an expert in emissions and alternative fuels, died on Monday while Fulvio Filace, 25, died on Wednesday night.
Their Volkswagen Polo TDI, equipped with the experimental technology, caught fire last Friday on the Naples ring road.
“We hoped to the end that Fulvio could be saved,” Prof Fabio Murena told Italy’s Ansa news agency. “We express our condolences to family and friends.”
Prof Murena is the husband of Ms Prati, who was driving at the time of the explosion.
Italy’s National Research Council mourned the two on Friday.
“The loss of two lives, moreover in such dramatic circumstances, deeply marks the scientific community, in every part of Italy,” the NRC said.
“In the next few days, as a sign of closeness and respect for the two victims and their loved ones, conduct of numerous events will continue to be reviewed and rescheduled.”
Mr Filace had been put in an induced coma after the explosion left him with third-degree burns covering 70 per cent of his body.
The fire service is investigating the contents of two gas cylinders on board the vehicle, which are believed to have caused the blast.
Naples public prosecutor's office has opened a homicide and fire investigation, and has seized a prototype of the vehicle.
The NRC said it was launching an internal inquiry into the deaths.
The Life-Save car, partly funded by the EU, is part of a plan to turn old engines into new hybrids.