The death of an 85-year-old man in Tilbury may be linked to a visit from a bogus caller, say Essex Police.
Henry Bojanowski, a World War II veteran who lived alone, died on Sunday, two days after a bogus caller tricked his way into his home.
Officers are investigating a possible link between the incident and Mr Bojanowski's death 48 hours later.
A police spokesman said a man called at Mr Bojanowski's home in Coronation Avenue claiming to be dealing with a water leak.
Passports missing
As the former RAF Lancaster bomber pilot allowed the caller into the kitchen, he saw a second man leaving his bedroom.
His British and Polish passports are both missing.
One man is described as white, aged 25 to 30, 5 ft 8 in tall, of medium build and tanned.
The second man was taller and of slim build.
Detective Constable Cliff Benton said: "This is yet another case where callous thieves have preyed on elderly victims."