A spokesman for Wiltshire Police told the Daily Mail detectives were making inquiries trying to unravel the circumstances surrounding Ellie's death.
"I would like to again thank the communities of Calne and Chippenham for the support and patience they have shown so far to our officers as they have carried out inquiries as part of this murder investigation."
Ellie was a year 12 pupil at Hardenhuish School in Chippenham and she had represented the school at a number of showjumping events.
Lisa Percy, head teacher of Hardenhuish School, told the Daily Mail: "I would like to thank everyone for all of the messages of support that we have received from past, present and future parents, colleagues and other members of the community.
"We would like to express our thanks to all partner agencies who have supported us too.
"The students, staff and parents have found comfort in being together and paying their respects to Ellie and our thoughts remain with her family and friends at this time."
Ellie's family, who have asked for privacy, released a picture of the teenager but did not wish to say anything further at this time.
- Daily Mail