A HEARTBROKEN mum has called for calm after her young daughter was stabbed to death in Southampton Sports Centre.

Stacey White revealed violent threats had been made to the family of a man who was arrested on suspicion of the murder of 13-year-old Lucy McHugh.

She is urging people to stop the speculation and threats, a move backed by police.

It came as Hampshire Constabulary revealed Lucy, sustained stab wounds before her body was discovered by a dog walker near the ski slop in the sports centre.

In a post on social media, Ms White, who works for a city care agency, wrote: “Please can I ask that people are not passing blame onto family members of the person that has been arrested in connection with my precious daughter Lucy’s murder.

“Making threats of violence to them will not bring my angel back.”

Last night, police confirmed Lucy’s cause of death, but were unable to say what the murder weapon was.

A 24-year-old man, who cannot be identified for legal reasons, remained in custody last night after he was arrested on suspicion of murder and having sexual activity with a child.

Officers were granted an extension on Saturday night in order to continuing questioning him. In an appeal for witnesses police have also released images of the type of clothing worn by Lucy before her death.

Detective Superintendent Paul Barton, pictured, said: “As we continue to investigate the circumstances of Lucy’s tragic death, we are repeating our appeal for the public’s help.

“We know how shocked the community is and understand that emotions are running high.

“However we ask people not to speculate on social media - it is unhelpful to the investigation and to Lucy’s family. Please allow us to do our job and find out what happened to Lucy.”

They are still trying to trace Lucy’s movements between 9.30am on Wednesday, when she left her house in Mansel Road East, and 7.45am on Thursday, when her body was found in woodland by a dog walker at the sports centre.

The clothing is described as distinctive black jacket with white sleeves, the logo for the band Falling in Reverse on the front and RADKE 01 in red on the back, a white vest top camouflage leggings and black and white Jordan 23 trainers

A home in Mansel Road East, near to where Lucy lived with her family, was searched by forensic officers, as well as nearby wasteland.

Friends of Redbridge Community School pupil Lucy, described by friends as “a bright spark”, will join together on Tuesday to release balloons in her memory on Mansel Park from 1pm. The youngsters are asking for people to join them by contributing 50p for a balloon as well as donate to a fundraising appeal to pay for Lucy’s funeral costs.