Singapore launched a contact-tracing smartphone app to allow authorities to identify those who have been exposed to people infected with coronavirus as part of efforts to curb the spread of the disease.
Governments around the world have turned to technology to battle the virus.
The TraceTogether app will work by exchanging short distance Bluetooth signals between phones to detect other participating users in close proximity of 2 metres.
Records of the encounters will be stored locally on each phone with the app, developed by Singapore's Government Technology Agency (GovTech) and the health ministry.
Users will need to send their logs when requested by the health ministry, which will otherwise not have any knowledge of the data, according to an official statement.
Singapore has won international praise for its fastidious approach in tackling the virus - which has included using police investigators and security cameras to help track suspect carriers.
The data stored on users' phones will be encrypted and the app will not access other information, such as a user's location.
"The engineering has preserved the privacy of the users from each other," Janil Puthucheary, a senior minister of state, told reporters.
Singapore has stringent rules to deal with infectious diseases - last month it charged a Chinese couple with giving false information about their movements to authorities looking to trace their contacts.
While downloading the app is not compulsory, the government said it would encourage people to do so.
TraceTogether's functionality will be suspended after the epidemic subsides, according to its description in the Apple App Store. (Writing by Aradhana Aravindan in Singapore)