A Japanese ministry is conducting an internal investigation after a Google Groups account used for international treaty negotiations was left on its default, publicly viewable settings.

An official at Japan’s Ministry of the Environment created the group to share mails and documents related to Japan’s negotiations during the Minamata Convention, a meeting held in Geneva in January to create international standards to limit international mercury use. But the official used the default privacy setting, leaving the exchanges open to searches and views in the months since. The information has now been removed.

“The majority of the information that was accessible was not secret, but we’re conducting an investigation into the details now,” said Michihiru Oi, a ministry official.

Over 6,000 items, including private contact information of officials, was publically accessible.

Oi said the ministry has its own system for creating groups and sharing documents, but it doesn’t always function well outside of Japan, sometimes leading to “poor connections” and a “bad working environment.”

Earlier this week the Yomiuri Shimbun, which has the highest circulation of Japan’s newspapers, said that over 6,000 items, including private contact information of officials, was publically accessible. The newspaper conducted a broader investigation and said Japanese high schools, health organizations and even political parties had left private details open to the public on Google Groups.

After the news broke, Japanese Minister of the Environment Nobuteru Ishihara hastily ordered a new data security group for the ministry to be formed to investigate the matter. The group held its first meeting on Wednesday.

The framework for the mercury treaty was agreed to in January, with the final version to be signed in Japan in October. It is named “Minamata” after the seaside city in southern Japan where thousands of residents were poisoned by mercury discharges from a local factory in the 20th century.