The passport numbers and Visa details of 31 world leaders were accidentally emailed to the organisers of the Asian Cup in Australia before the G20 summit in Brisbane in November 2014.
Those affected included US President Barack Obama and German Chancellor Angela Merkel.
A worker at the Australian Department of Immigration sent the list by mistake.
The department decided there was no need to alert the G20 attendees.
“Given that the risks of the breach are considered very low and the actions that have been taken to limit the further distribution of the email, I do not consider it necessary to notify the clients of the breach,” an unnamed Depart of Immigration director wrote to the Australian Privacy Commissioner in an email obtained by the Guardian following a Freedom of Information request.
Both the sender of the email and the recipient had deleted it within 10 minutes of it being sent, the officer explained, and the Asian Cup football tournament organisers said they did not believe the email was accessible or stored on their servers.
The message included the 31 world leaders’ dates of birth but not personal addresses and other contact details.
The breach was said to be the result of “human error”, with the sender forgetting to check the auto-fill function in Microsoft Outlook’s email service before hitting send.
“There was nothing systemic or institutional about the breach,” continued the email from the government official.
“It should also be noted that the personal details of these individuals, including their names, positions and dates of birth are generally already available in the public domain given their prominent positions.”
Fifteen years ago, Vladimir Putin was elected promising to make Russia strong again: a country its citizens could be proud of and that the world would respect.
This week, Russia’s main polling agency measured his support rating at 85%.
While opinion polls do not tell the full story in a country where much of the media is under state control, Mr Putin’s enduring popularity is undeniable.
“Russia and Putin go together, we just don’t see another way,” says Oleg Sokolov, a member of the latest pro-Putin youth group known as Set’, or “Network”.
Set’ has its headquarters in a converted Moscow gas tower. The office resembles an internet start-up or a PR firm, strewn with bright-coloured bean bags and dotted with young Russians eating sushi or browsing their iPads.
But the brand they’re promoting is Vladimir Putin: his image is plastered all over the walls alongside signs reminding Russians of what makes their country great.
The group won’t comment on any formal links to the Kremlin but their passion for the cause is clearly genuine.
“Putin is a strong leader, I’d say the strongest in the world right now,” Oleg says.
Three men convicted of involvement in the Kunming knife attack have been executed, a court in China says.
Iskandar Ehet, Turgun Tohtunyaz and Hasayn Muhammad were convicted in September of murder and terrorism offences.
The attack at Kunming station in March 2014, left 31 people dead and more than 140 injured. It caused shock across China.
Beijing blamed it on Muslim extremists from Xinjiang, next to Central Asia.
Xinjiang is home to the Muslim Uighur minority. It has seen a series of violent attacks and clashes which Beijing blames on separatists inspired by terror groups outside China.
Uighur activists say the suppression of residents’ cultural and religious freedoms is fuelling unrest in the region and attacks elsewhere in China.
Police say three men did not take part in the station attack but had trained others for terror activities, the Xinhua state news agency reported. They were arrested two days before the attack, as they were trying to leave China.
They were put to death on Tuesday, the Kunming City Intermediate People’s Court said.
Police shot dead four other assailants during the attack. One woman has been jailed for life.