Hong Kong CNN Business  — 

Samsung is in trouble in Australia over ads that suggested its Galaxy smartphones could be used while swimming.

The country’s competition regulator filed a lawsuit against Samsung, alleging that the ads were misleading. Samsung touted its devices as being water resistant up to 1.5 meters deep for 30 minutes, and showed them being used in oceans and swimming pools, the regulator added.

“Samsung’s advertisements falsely and misleadingly represented Galaxy phones would be suitable for use in all types of water, including in ocean water and swimming pools, and would not be affected by such exposure to water,” Rod Sims, chair of the Australian Competition and Consumer Commission, said in a statement on Thursday.

Australian officials say says ads like this one, touting Samsung's phone as water resistant, were false and misleading.

Samsung, the world’s biggest smartphone brand, said it would defend itself against the lawsuit.

The case involves more than 300 Samsung advertisements on television, radio, online and on social media since February 2016, and covers 15 Galaxy models including the Note 7, the A8 and the latest S10 series.

If the suit is upheld, Samsung could face fines worth millions of dollars. Following a recent change in the law, the maximum penalty for each violation after September 1, 2018, is 10 million Australian dollars ($7 million).

The Australian regulator said that Samsung didn’t have “a reasonable basis” for claiming its phones were water resistant because the company refused to honor warranties on some devices that were damaged when used in water.

Moreover, the regulator noted, Samsung’s claims are undermined by a warning on its website that the new Galaxy S10 phone range is “not advised for beach or pool use.”

The regulator said Samsung denied warranty claims from customers whose phones were damaged when used in water.

Samsung is the second largest smartphone brand in Australia, behind Apple (AAPL). The South Korean company sold more than 4 million devices in Australia last year, according to research firm Canalys.