Dozens of families have contacted ITV London over the treatment of their loved ones at Basildon Hospital.
The hospital is one of 14 across the country currently under investigation, because of higher than expected death rates.
The probe by the NHS Commissioning Board was ordered in the wake of failings at Stafford Hospital, where neglect and abuse led to hundreds of unnecessary deaths.
For this special report, Paul Brand spoke to two families, who claim the deaths of their relatives following treatment at Basildon Hospital could have been prevented.
More top news
Hundreds of people march for more affordable homes and control private rents in London.
Police proposals suggest that all frontline police officers should have the option of arming themselves with Tasers.
A British military healthcare worker is being monitored at the Royal Free Hospital following a needle-stick injury in Sierra Leone.