Smartphones from Apple, Xiaomi and others have been violating Taiwan's privacy laws by collecting user data and sending it back to company servers, according to a government regulator. The handset makers could face fines or a ban unless they address the breaches, according to Taiwan's National Communications Commission (NCC).

Taiwan's government began to review privacy standards two months ago after media reports said smartphones made by Chinese firm Xiaomi Technology could be sending user data to its home servers in mainland China without users' permission.

The investigation found that some of the smartphones could allow manufacturers to collect users' data without permission. Both Apple and Xiaomi were named, but on Friday the commission declined to list which other vendors were being probed.

The Taiwanese government will ask the offending brands to modify their handsets. If they refused, the NCC could fine the companies up to T$200 million ($6.43 million) or ban their handsets from being sold in Taiwan.