Johnson & Johnson

The case, expected to last six months, will involve women who claim their lives have been ruined by a vaginal medical device made by Johnson & Johnson.

It is designed to treat common complications from childbirth.

The firm behind the class action, Shine Lawyers, claimed about 8000 women could have been affected by mesh and tape surgical implants used to fix pelvic-floor damage from prolapse and incontinence.

The true number of Australia women affected is the subject of a senate inquiry. Estimates range from 3000 to 30,000 women.

The firm said the vulnerability concerned its OneTouch Ping pump which is only sold in the US and Canada.

However, it told the BBC there had been no reported attacks and the risk was "extremely low".

"It would require technical expertise, sophisticated equipment and proximity to the pump," it said.

The disclosure was made in a letter to patients on 27 September, the firm said.