A 15-year-old girl who is thought to have died after taking ecstasy was "a thoughtful, beautiful girl, who was much loved", her mother has said.
Leah Heyes died after she collapsed in a car park in Northallerton, North Yorkshire, at about 9.30pm on Saturday.
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On Tuesday, her mother Kerry Roberts said: "Leah was my best friend.
"She was a thoughtful, beautiful girl, who was much loved. She was fun, bubbly, and had a great sense of humour.
"I'm absolutely heartbroken to have lost my beautiful girl.
"No words can describe how much she will be missed and the enormous gap she has left in our lives.
"She will be truly missed more than words can say. I love you always."
Two teenagers, aged 17 and 18, have been arrested on suspicion of being concerned in the supply of class A drugs following Leah's death.
They have been released under investigation.
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Detectives have appealed for mobile phone footage believed to have been taken on the evening of Leah's death.
Detective Inspector Eamonn Clarke said: "We have had a good response to our recent appeal for information but we know there are still people out there who have yet to come forward.
"Inquiries also reveal that there may be mobile phone video footage of the events of that tragic evening.
"This footage will be extremely helpful to our investigation and we are appealing to anyone who has footage on their phone, has been shown footage or knows of anyone who has such footage to come forward."
Police said there were around 20 people in the area of Applegarth car park on Saturday night and appealed for them, and anyone else who was passing through, to contact them.
Mr Clarke said: "A young girl with her whole life ahead of her and everything to look forward to has died, a family has been devastated and a community left in shock. It is vital that people come forward and help us find the answers for Leah's family and friends.
"Taking drugs appears to have become the norm and more socially acceptable, but the fact is it can have utterly tragic consequences and it needs to stop.
"This devastating case must be the catalyst for people in the community to stand up and help us put a stop to drug dealing."
Anyone with information is asked to call North Yorkshire Police on 101 and ask for Northallerton CID or contact Crimestoppers anonymously on 0800 555111.