Three people known to Sara Sharif flew to Pakistan the day before the 10-year-old’s body was discovered by police.
One-way tickets to Islamabad were booked on 9 August, hours before she was found dead at a home in Woking, Surrey.
Police launched a murder investigation and said they wanted to question three people known to her who had left the UK.
Sara Sharif was found dead at a home in Woking
Detectives are working with international authorities to locate the trio.
Police said on Tuesday that formal identification was still set to take place and a post-mortem examination would be carried out.
Sky News visited the Woking-based travel agent where the flights to Pakistan were booked and saw copies of passports and tickets for the passengers.
The tickets cost just over £5,100 in total.
The travel agent told Sky News the tickets were booked after a phone call and communication on WhatsApp.
