The funeral of Donegal teenager Tory Johnston is taking place in Donegal on Sunday.
The 17-year-old Leaving Cert student died suddenly following a night out with friends in Letterkenny last week.
Gardaí confirmed they made significant progress in to her death.
The 17-year-old Leaving Cert pupil suffered what appeared to be a number of seizures before passing away at Letterkenny General Hospital shortly after 6.30am on Wednesday morning.
Gardaí issued an appeal to more than 630 nightclub patrons who attended the club to contact them on a special email address.
Local Garda Inspector Pat O’Donnell confirmed on Saturday that they have made significant progress with their investigation following the appeal.
A postmortem by assistant state pathologist Dr Michael Curtis was "undetermined" and gardaí will now have to wait for the result of toxicology reports.
A book of condolences opened on Saturday at the school, Loreto Secondary School in Letterkenny, where Ms Johnson had just been made a prefect.
She is survived by her parents Helen and Sammy and sister Amy.
Her uncle Joe Dorrian, a local Garda Sergeant, said his niece lived for "fashion, make-up and school" and said the night she took ill was only her second time at a "real" disco.
The funeral takes place at St Eunans Cathedral with burial afterwards at Conwal Cemetery.