Police officers have been criticised over their handling of the search for a 77-year-old man with dementia who was found dead in snow – after it emerged a passer-by raised concerns about a man wandering alone hours earlier.

The Met Police has changed its missing persons procedures after the body of William Lee, of Pellerin Road, Stoke Newington, was found on March 25 in Barnet, near to where officers has spoken to him the night before.

Because of freezing conditions the Met’s missing persons unit was on high alert after Mr Lee was reported missing four days previously from his home.

The investigation into his death from hypothermia has revealed that a member of the public called police about a man fitting Mr Lee’s description, seen in Mays Lane at 8.10pm, the night before he was found.

He didn’t respond when the woman tried to speak to him and she then pointed him out to a police officer who was dispatched to another incident in the area.

Mr Lee told him the policeman had been out for a few drinks with a friend and was on his way home from the pub, and walked away after a brief conversation.

Mr Lee’s daughter, Isabelle, 36, is upset the officer accepted her father’s explanation without checking his name, and failing to realise his condition or that he had been reported missing.

Ms Lee, of Archway, Islington, said: “I am quite angry and depressed about all of this. I feel let down by the officer that spoke to my father.

“I cannot get to grips with the fact that an authority like the police – who we’re supposed to believe will help us – had the opportunity to help my father on several occasions and did not, even when a passer-by voiced her concerns more than once.”

The record producer, who wrote a song in her dad’s memory to raise awareness of dementia, added: “The heartache and mental torture is unbearable at times when I think how my dad may have suffered, and I miss him more than words can say.

“I just want to know why they didn’t help him and for them to apologise for what has happened,” she added.

Det Ch Insp Barry Loader, who leads the missing persons unit in Hackney, said it was not possible to state categorically that the man officers found wandering was Mr Lee, but that it was highly likely it was him.

The Met is considering the wider distribution of missing person photographs in future.

“The most significant learning from this incident is to spread the circulation of briefing slides wider across the organisation,” he said.

“Even if Barnet borough had been sent a briefing slide, the officers from the safer transport command work across different boroughs and it’s unlikely they would have known he was missing.

“The Met is working with Alzheimers.org and recently trained a number of staff to become dementia champions, further training days are being put together.”