Police confirmed no-one had yet been arrested but interviews had been carried out under caution.
Representing some of the families affected, Emma Jones, from Leigh Day Solicitors, said the news was “small comfort” to her clients – who she praised for showing “immense patience and fortitude” while the investigation has been carried out.
“They have already waited many years for answers into the deaths of their loved ones and progress in this investigation does not appear to have been fast,” she said.
“We urge Kent Police to complete their investigations without further delay so that inquests into unexplained deaths at Gosport War Memorial Hospital can be re-opened as soon as possible.”