Potentially sub-standard breast implants made by a French prostheses maker now under investigation were sold to about 1,000 Dutch women under a second name, broadening the scope of the scandal that could already affect some 300,000 women worldwide.

A Dutch healthcare authority spokeswoman told Reuters on Monday that a Dutch company had bought implants made by France's Poly Implant Prothese -- which went bankrupt in 2010 after French health authorities shut its doors -- and sold them in the Netherlands rebranded as M-implants.

We estimate that some 1,000 women in the Netherlands have those implants ... We have advised them to consult their physician, spokeswoman Diane Bouhijus said.

She declined to disclose the name of the Dutch company.

The rebranding of PIP implants potentially expands the scope of the health controversy in which PIP -- once the third-largest maker of breast implants in the world -- stands accused of using industrial-grade instead of medical-grade silicone in some of its prostheses, which were sold from Europe to Latin America.

The company's founder, Jean-Claude Mas, was able to charge lower prices for the implants using the non-approved silicone.

Health authorities have cited no evidence of increased cancer risk due to the PIP implants, but have said they have higher rates of rupture that could cause inflammation and irritation.

While the French government has urged the 30,000 women in France with PIP implants to have them removed, other countries -- including Britain and Brazil -- say that women should visit their surgeons for checks.

Health spokeswoman Bouhuijs did not say how long M-implants were sold in the Netherlands before they were banned in March 2010, along with PIP-labelled implants, as in France.

In early 2010 Dutch authorities launched an investigation into breast implants which is still ongoing, Bouhuijs said.

France's drug and medical device regulator, AFSSAPS, was closed on Monday due to the holidays, so Reuters was unable to ascertain whether health authorities knew about the M-implants.

SICK IN SOUTHERN FRANCE

Mas's lawyer Yves Haddad told Reuters on Monday that his 72-year-old client is in poor health, but ready to respond to any court summoning.

No one has been charged in the case, but sources say a Marseilles court could soon announce fraud charges against four to six ex-PIP employees. An investigation into involuntary homicide is ongoing, following the death from cancer in 2010 of a woman who had PIP implants.

Haddad denied that Mas was in hiding, reiterating that he was still in southern France's Var region.

He's currently in very bad health because he has just undergone a difficult surgery that prevents him from walking, Haddad said.

The news that Mas had recently been operated on was confirmed by a second source, who cited a vascular problem.

He is worried by the importance this matter is taking on. He is angry at those who pointlessly add to people's suffering, said Haddad.

Haddad denied reports that Mas was a former butcher, saying that before founding PIP in 1991 he worked for more than 15 years as a medical sales representative for Bristol Myers.

(Writing by Alexandria Sage; reporting by Ivana Sekularac and Jean-Francois Rosnoblet; editing by Geert De Clercq)