Samsung has boosted the camera capabilities on the Galaxy S9 smartphone, continuing with a similar design to the S8.

Samsung smartphones are sending users' pictures to their contacts without their permission, according to complaints by a number of people posted online.

The issue appears to be affecting Galaxy S9 and Galaxy Note 8 users.

One user on Reddit said that the entire photo library on his phone was sent over text to his girlfriend but there was no record of it on his messaging app. He discovered it had happened via his T-Mobile logs.

Users are reporting that it is an issue with Samsung Messages, the default messaging app on the South Korean company's devices.

One person on Samsung's community forum said the messaging app became "very buggy" after an update by T-Mobile for so-called Rich Communication Services (RCS) messaging. This new standard is a messaging protocol between different carriers to help make sending videos and other media easier. It is aiming to replace traditional SMS messaging.

A Samsung spokesperson told CNBC by email that it is aware of the reports and that the technical teams "are looking into the matter." Customers "are encouraged to contact their local customer service team directly," the spokesperson added. Later, Samsung updated the statement to say that it had investigated the issue and found that there was no software or hardware problem.

"Samsung has reviewed this matter thoroughly these past few days; however, there were no hardware or software issues found to be relevant to this particular case. While there have been no known similar customer reports globally, we will continue to investigate this issue further," a spokesperson told CNBC by email on Tuesday.

T-Mobile was not immediately available for comment. But the mobile network did issue a statement to other news organizations saying that "it's not a T-Mobile issue."