The BBC's Stephen Cape: "Officers are confident they will eventually catch the murderer"

Detectives are in no doubt that the 17-year-old student was murdered after her naked body was found in a water-filled ditch 25 miles from her home in Trimley St Mary, Suffolk.

But senior officers said a post-mortem examination had proved inconclusive as there were no obvious signs of death, such as stab or gunshot wounds.

Police believe that Vicky, who vanished while walking home from a nightclub in Felixstowe two miles from her home, may have been strangled or suffocated.

Police issued photos of the clothes Vicky was wearing

Det Supt Roy Lambert, heading the investigation, said it was so far impossible to say whether Vicky had been raped.

He said: "As Vicky was found naked one of the main lines of inquiry at the moment is to trace the clothes she was wearing when she went missing."

Vicky vanished after walking back from the Bandbox nightclub in Felixstowe.

She had walked part of the way with friend Gemma Algar, but the pair parted at around 2.30am on Sunday, 19 September.

Vicky was wearing a short black dress, brown jacket and platform-heeled black sandals and carrying a small half-moon shaped black purse.

'Undiluted evil'

On Monday the school attended by the murdered teenager, Orwell High, in Felixstowe, said it was saddened to hear of her "tragic death".

In a statement the school said: "Our thoughts and prayers are with Vicky's parents, Graham and Lorinda and brother Steven.

Forensic teams combed the area where Vicky's body was found

"She was a lovely girl who will be greatly missed by her friends and teachers.

"We echo the concerns of the community and hope that Vicky's killer is found quickly."

Prayers were said on Sunday for Vicky and her family at a church in Trimley St Mary.

Local vicar, the Rev Rod Corke said the community was "hurt and broken" by the "undiluted evil" which had taken away a "bright, vivacious young lady with everything to live for".

Rubbish searched

He said he had visited Vicky's parents Graham, 45, and Lorinda, 43, several times over the weekend.

"Considering what they have gone through they are bearing up well. But they are devastated," he said.

"No one can imagine what it must have been like for them over the past week."

Vicky's body was found on Friday in a water-filled ditch in Creeting St Peter, 25 miles from her home.

Police have appealed for anyone seeing vehicles arousing suspicion in Creeting St Peter during the last week to get in touch.

Officers also plan to search bin bags in the village to check whether the killer may have dumped Vicky's clothes before making his getaway.