Police are investigating why there was a three-day delay before the family of an autistic man were informed of his death.
Rodney Larsh, 20, who lived at a care home in Chingford, went missing shortly after 10am on Christmas Eve and was killed by a train while walking on tracks at Shenfield station the same day.
Despite his body being discovered, his desperate family continued to search for him and were not informed until three days later.
Police have admitted the delay, but have not revealed what caused it.
Mr Larsh had been staying with his two sisters, 25 year-old Jessica Larsh and Rosemary Nkestiah, 31, in Barking when he went missing.
Conscious of his vulnerability and inability to communicate verbally, the sisters raised the alarm immediately and told police he was at high risk.
But despite the sisters giving consent for an immediate public appeal, one was not issued until Christmas Day – a day after his death.
On Boxing Day, police informed the sister’s about his travel movements based on his freedom pass activity and a search party visited Liverpool Street station, where Mr Larsh had been on Christmas Eve.
Police then arrived at the family home shortly after 11am on December 27 to inform them of Mr Larsh’s death.
Ms Nkestiah said: "We were completely shocked. For the previous 72 hours we were hoping and praying he was going to come back.
"The day before we organised a search party to go to Liverpool Street station in the hope that he would be found, when all along he had been killed the day he went missing.
"From the moment we reported him missing, all we heard from the police was ‘things are slower’ and repetitive responses such as ‘it’s the time of year'".
Ms Nkestiah believes the delay in giving the family the tragic news was because there was “no sense of urgency” and information from officers was “inconsistent”.
A spokeswoman for the Metropolitan Police said: "We are aware of an issue which resulted in a delay in informing the family of Rodney Larsh of the discovery of his body.
"This is being looked into and we are in contact with the family about this matter."
The sister's dispute this claim and say they have not had any contact from police since December 30.
An inquest into the death of Mr Larsh opened yesterday and has been adjourned until later in the year.