James McMullan, from East London, was with friends at the Barrowboy and Banker pub on Saturday night.
The 32-year-old stepped outside for a cigarette, and agreed to meet the rest of his friends once they had finished their drinks.
When the attack began, James’ friends were rushed upstairs to safety and he became separated from the group.
Now, his heartbroken sister has confirmed that he was one of the seven people killed in the attack on London Bridge and Borough Market.
"This morning we received news from police that my brother's bank card was found on one of the bodies from Saturday night's brutal attack," Melissa McMullan told Sky News.
"They are unable to formally identify him until the coroner's report begins tomorrow.
"We would like to send our condolences to the relatives and loved ones of all the people who lost their lives. Our thoughts are with them also at this time.
The sister of 32-year-old James McMullan says she believes he was killed in Saturday's attack in London pic.twitter.com/3WLv4XbU5w
— Sky News (@SkyNews) June 5, 2017
"We would like to thank all the members of the services who did their utmost to serve and protect the population of London from these deranged and deluded individuals."
Melissa described her brother as a "generous and caring friend".
"Words will never be able to match his essence, there will only ever be one James," she said.
"Nowhere else will you find such humour and unique personality, with someone who puts friends and family above all else.
"He was an inspiration."
James is the second victim of the attacks to be formally named and identified - the first was 30-year-old Canadian Christine Archibald, who is believed to have died in the arms of her fiancé, Tyler Ferguson, after she was struck by the attackers' van on London Bridge.
Her family confirmed the death of their "beautiful, loving daughter and sister" in a statement.
"She had room in her heart for everyone and believed strongly that every person was to be valued and respected," the statement said.
"She lived this belief working in a shelter for the homeless until she moved to Europe...She would have had no understanding of the callous cruelty that caused her death.
"Volunteer your time and labor or donate to a homeless shelter. Tell them Chrissy sent you."
Chrissy was in London with Tyler for the weekend when she was killed.
Her sister, Cassie Ferguson told CBC News in Canada that Tyler is "broken into a million pieces" after her death.
"He held her and watched her die in his arms," she said.
A 21-year-old Brisbane woman is still among those missing following the attacks.
Sara Zelenak was separated from her friends on Saturday night and was last seen on London Bridge. Friends and family have been unable to get in contact with her since the attacks.
Her step-father, Mark Wallace, said they have not heard from her in 48 hours and authorities have not been able to give them any news on her whereabouts.
He told the Daily Telegraph Sara was meant to be babysitting the night of the attacks, but the children's grandma stepped in a the last minute so she went out with friends instead.
"I've contacted every hospital in London," he said.
"I feel terrible, I don't know what my name is, I can't think."
If any Australians are concerned about family and friends and unable to contact them they should call 1300 555 135 or +61 2 6261 3305 if overseas.