Foreign Minister Julie Bishop has now confirmed that two Australians died in the London terror attacks over the weekend.
She was "deeply saddened" to announce the deaths, and is working with UK officials to confirm the identities of the dead before releasing their names.
While the family of nurse Kirsty Boden have already paid tribute to the 28-year-old, 21-year-old Sara Zelenak from Brisbane is still missing after last seen running from the three attackers and her family said they have been bracing themselves for the worst.
"We continue to work with the United Kingdom authorities who have asked that we await official confirmation of the identities of the victims, and for the families to be officially notified, before we release their names," Ms Bishop said in a statement on Wednesday morning.
"The Australian government has remained in close contact with the families who have requested privacy."
Kirsty, from the town of Loxton in the state of South Australia, was running to help victims of the senseless attack when she was fatally injured.
It’s unclear whether the volunteer lifesaver was killed when a trio of fanatics ploughed a white van into pedestrians on London Bridge or afterwards, when they stabbed people as part of their deadly terror-driven rampage.
Her family said in a statement: “Kirsty was loved and adored by her family, friends and boyfriend. She was the most outgoing, kind and generous person who loved to help people. Helping people was what she loved to do in her job as a nurse and in her daily life.”
“As she ran towards danger, in an effort to help people on the bridge, Kirsty sadly lost her life. We are so proud of Kirsty’s brave actions which demonstrate how selfless, caring and heroic she was, not only on that night, but throughout all of her life. Kirsty – we love you and we will miss you dearly.”
“We will not be making any further comments on this tragedy and ask everyone, especially the media, to give us the privacy we need to grieve away from the public eye.”
WATCH: Kirsty Boden lost her life trying to help others. Post continues...
Kirsty worked at Guy's Hospital, around 300 metres away from London Bridge, as a staff nurse in Theatres Recovery.
Dame Eileen Sills, Chief Nurse at Guy’s and St Thomas’ NHS Foundation Trust, said: “Kirsty was an outstanding nurse and a hugely valued member of the staff team in Theatres Recovery, described by her colleagues as ‘one in a million’ who always went the extra mile for the patients in her care.”
“Our thoughts at this time are with her family, her loved ones and our staff who have lost a dear friend and colleague.”
Seven people lost their lives during the horrific attacks and dozens more were injured.
Prime Minister Malcolm Turnbull confirmed four Australians were caught up in the London attack.
“There are two other Australians, so that brings it to a total of four, about whom we have very real concerns, but at this stage we're not able to say anything more,” he told reporters in Sydney on Monday.
"We have been in touch with their families, in close touch with their families, as we seek to find confirmation of [their] circumstances."
There are grave concerns for a Brisbane woman who has not been heard from since she was last seen on London Bridge before the weekend’s terror attacks.
Sara Zelenak, 21, who works as an au pair in the capital, has failed to make contact with friends and family since the deadly attack in which she became separated from friends.
A social media campaign has been created in the hopes of locating the young woman, and her mother has travelled to the city in an attempt to step up search efforts.
As reported by 9 News, Queensland woman Candice Hedge has undergone surgery for a stab wound to the neck, while Darwin man Andrew Morrison also sustained injuries during the Saturday night attack.
Taking to Facebook Candice, who has been working in hospitality in London for just under a year, assured her loved ones she was doing OK: "Hey everyone, just so you know I'm doing Ok. Bit of pain but I will survive. Thanks for your thoughts and well wishes. Love to all."
Meanwhile, the moments after Andrew's terrifying injury have been captured on a video which has surfaced online.
"[I] walked outside, walked across the road and a fight breaks out and I'm like 's---' what's going on here?' I start to walk towards it and all of a sudden a guy comes up to me with a knife, stabs me and I push him off, blood is going everywhere," he explains as he nurses his neck wound. "He got me, but I dodged it. I ducked and weaved.”
Foreign Minister Julie Bishop said he had received stitches for his wound and was on his way home to Australia.
WATCH: Andrew Morrison calmly recounts the details of his attack.