The police investigation into one of Norfolk's most notorious cold cases has been criticised by a former officer and witnesses.

Schoolgirl Johanna Young was found dead in a water-filled pit in woods near Griston Road, Watton, on Boxing Day 1992, sparking the county's biggest ever murder inquiry. The 14-year old had gone missing on the evening of December 23.

A podcast by this newspaper, called Unfinished, is currently exploring the case and hears from people who have never spoken about it.

When Johanna's body was found, Detective Superintendent Mike Cole, who led the murder inquiry, said he was looking for a 'calm, brutal killer.'

But evidence later gathered by police, suggested that Johanna may have been killed by accident.

She is believed to have been knocked unconscious by banging the back of her head in a fall.

The person she was with then dragged her body to the pit, believing she was dead.

Evidence suggests a second person helped them move the body.

Peter Walmsley, who was a PC in Watton and the police's press spokesman at the time, said he remembered debating with Det Supt Cole about whether they should adapt their approach to encourage the accomplice, or people close to the killer, to come forward.

He said: 'I remember Supt Cole having a real go at me about this because I said, if you put this out as manslaughter and not murder you might get someone to come in.

'He (Det Supt Cole) went absolutely bonkers at me. He said, 'don't you dare put that out'.'

Johanna's teacher at Watton High, Jan Godfrey, also said a gentler police approach could have made a difference.

'The police reacted immediately and said this awful murder rather than, we don't know what happened,' she said.

Mr Cole declined to comment for the podcast.

Vivian Sellers, meanwhile, who ran a taxi firm in Watton at the time, also criticised the way police dealt with her.

One of their cars, a red Peugeot, was seen by a witness driving around Watton the night Johanna went missing.

But Mrs Sellers said one officer later asked her to change her log from that night, so the times would suit what the witness told them.

Mrs Sellers said: 'He was trying to manipulate me to say I wasn't sure that that was the right time.'

At least 40 detectives worked on the inquiry at the time and Mrs Sellers did not remember which officer she spoke to. Norfolk police declined to comment.

•You can listen to the podcast on the link above or by searching for Unfinished in your normal podcast provider