Samsung, the flagship subsidiary of South Korea's biggest business group, suffered a humiliating recall of its Galaxy Note 7 device in 2016, and was then embroiled in the sprawling corruption scandal that brought down ousted president Park Guen-hye.

But its Galaxy S8 smartphone was a consumer and critical success and financially it has gone from strength to strength.

It enjoyed net profit of more than 42 trillion won ($39 billion) last year, and this month Lee Jae-yong, heir to the founding family, was released from prison after most of his bribery convictions were quashed on appeal.

Visually they will resemble their predecessors but with a slightly smaller bottom bezel, a spate of leaks suggest.

Both Galaxy S9 and Galaxy S9+ have upgraded cameras with variable apertures capable of shooting up to 960 frames per second for "super slow-motion" videos, according to tech website WinFuture, and stereo speakers.

Samsung has also revamped the series' internals with faster processors, it added, and their batteries -- the issue at the heart of the Galaxy Note 7 debacle - can last a full working day.