Officers arrived at Kane Gorny’s bedside, but were told by nurses that he was in a confused state and were sent away.
The keen footballer and runner, 22, died of dehydration a few hours later.
A coroner had such grave concerns about the case that she referred it to police.
His mother Rita Cronin, a civil servant told Westminster Coroner’s Court that staff tutted at her and repeatedly refused to listen to her concerns that her son hadn’t been given vital medication.
At one point he became so desperate and upset that staff sedated and restrained him – and on the night before his death, his mother said, he was not checked on by medical staff, despite being in a room on his own.
Following his death, a nurse allegedly inquired whether the family, from Balham, South-West London, was ‘finished’ and asked a matron in front of them whether she could ‘bag him up’.
Mr Gorny, who worked in Waitrose and was training to be a locksmith and shoe repairer, had survived a malignant brain tumour in 2008.