Alison Patey-Colton, an aunt of cousins Natalie Perkins, 20, and Laura France, 18, said the girls had been having the "time of the lives" on their trip.

At a news conference in Sheffield, where both girls lived, she said the two were six weeks into an eight month trip.

She said the pair had worked hard and saved up for the trip round the world.

I do not think there are any words that can express the feeling of losing two very, very important people out of our family

Alison Patey-Colton

Mrs Patey-Colton, who is the sister of both girls' mothers, said she was reading a public statement to correct some misreporting of how the family first heard of the tragedy.

She said: "The parents discovered about this tragic event on Saturday evening as a result of watching the news."

She added: "Both families have suffered a terrible loss and are dealing with this in the best way they can.

"We have suffered a double tragedy which has affected all of the family very deeply.

"At this stage both Laura and Natalie are missing presumed dead.

"Arrangements are currently being made for both fathers to travel to Australia although specific details are yet to be finalised."

Mrs Patey-Colton said the two cousins were very close

She said Natalie had been travelling while she took a career break and Laura was due to start a course at Sheffield Hallam University in the autumn.

She said: "Laura is a beautiful young woman and very precious and adored by all of us.

"Natalie is a beautiful girl, perfect daughter, and is worshipped by her mum and dad."

Mrs Patey-Colton read her statement at South Yorkshire police headquarters in Sheffield, sitting with her husband Steve.

Asked about her feelings, she said: "I do not think there are any words that can express the feeling of losing two very, very important people out of our family."