An increasing number of women in the US have sued pharmaceutical company Johnson & Johnson, arguing its talcum powder caused their ovarian cancer.

Approximately 700 lawsuits have been brought to date, an American investigative journalist has estimated, with the number “still going up”.

“There probably will be more,” FairWarning reporter Myron Levin told Public Radio International.

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The white powder is made from talc, a very soft mineral mined from rock. Photo: Getty

Talcum powder has been sold by Johnson & Johnson as a personal hygiene product for more than 100 years, especially for women.

The research is as yet divided on whether the powder can cause cancer. The UN World Health Organisation (WHO) has described talc as “possibly carcinogenic”, while other health bodies have found little evidence to support this.

One theory is that talc particles travel to the ovaries, causing inflammation that can trigger the growth of tumours.

The company has defended the safety of its product.

“Few ingredients have demonstrated the same performance, mildness and safety profile as cosmetic talc, which has been used for over 100 years by millions of people around the world,” said Johnson & Johnson in a statement on its website.

In the only US talcum powder case to reach a verdict, a jury in 2013 did not find past medical research convincing enough, and thus did not award a female claimant any compensation, but still found that Johnson & Johnson should have warned consumers of potential risks.