At least 303 cases of unauthorised access were confirmed between late May and June 14, including three that involved cash trades resulting in financial loss, a Line spokesman said without providing further details.
"We are cooperating with police in investigating the cases, and we are calling for users to change passwords," the spokesman said.
The accounts were hacked "presumably after shared passwords with other online services were leaked somewhere else," he said, adding that to the company's knowledge, all of the breaches occurred in Japan.
"Line's system itself has suffered nothing abnormal. It is not that our system was hacked," she said.
A police spokesman said the case was under investigation.
Set up in 2011, Line now has more than 400 million users, mainly in Japan and mainland Asia, and is growing fast.
The service lets users make free calls, send instant messages and post photos or short videos, combining attributes from Facebook, Skype and messaging application WhatsApp.
Line has forged heavyweight partnerships with football clubs FC Barcelona and Real Madrid, brands such as Coca-Cola and tennis star Rafael Nadal.
One of Line's main selling points is its "stickers" -- funny, cartoon-like figures that users can post to friends.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
