PARIS: France's health minister called on Saturday for the head of the breast implant maker accused of selling faulty prostheses to tens of thousands of women around the world to be found, calling the growing scandal a "shady business."

Jean-Claude Mas, 72, the founder and CEO of French company Poly Implant Prothese (PIP) has not been seen or heard of in public since the scandal broke, potentially affecting 300,000 women around the world.

His company is accused of using sub-standard industrial silicone in some of its implants, which were sold globally before being taken off the market in 2010.

"It's obvious we have to find him (Mas) and those who had an interest in this company," French Health Minister Xavier Bertrand told Europe 1 radio on Saturday. "They have to answer for their actions."

"It's a shady business with lots of money involved," Bertrand said. "In not using the advertised product (silicone) they tried to make some money, that's the worst of it, on the health of women."

PIP's lawyer has said Mas and the company's chief financial officer were keeping silent "out of decency and discretion" but were still in the south of France.

On Saturday, international police agency Interpol confirmed that it had issued a so-called "red notice" for Mas, but said it was unrelated to his activities at PIP.

Interpol said the notice was related to an incident in Costa Rica in June 2010, when police there say he was arrested for a drunk driving offence but fled the country and did not show up for a court date.

Mas was briefly questioned by police in November 2010 but has never been summoned to court. A judicial source has told Reuters, however, that between four and six executives could be charged by a Marseilles criminal court for aggravated fraud.

Also on Saturday, France's national health insurance agency said it planned to sue over the PIP affair, alleging dishonest practices and fraud. Defendants will be listed as "persons unknown," a routine practice in France when the identity of an opposing party or parties is not yet determined.

"We think there was fraud starting with the very first (PIP implant) operation," the agency's director Frederick Van Roekeghem told France Info radio.

France's health ministry urged removal on Friday of the 30,000 PIP implants purchased by French women and said public health funds will be used to finance those extractions.

Just how the apparent fraud was covered up is the subject of controversy, with varying accounts of who knew what at the firm in an industrial town outside the southern city of Toulon.

Undated photographs that accompanied news stories in 2010 and were taken by a photographer for the regional newspaper Var-Matin showed workers in blue gowns filling rows of prostheses with silicone gel.

Masked and gloved, they looked as if they worked at an above-board professional health company.

But French health officials discovered last year that PIP was using a home-made brew of silicone, an industrial variety not approved by health authorities.

"You had to have been a chemist to have noticed anything," a former PIP worker and union chief, Eric Mariaccia, told Reuters.

"The responsible ones aren't the workers but the heads of the company, notably the four who were linked to production and thus responsible for their quality," he said.

At the company, which eventually shut its doors in 2010 after bankruptcy, Mas gave the orders, even though he was technically in retirement and CFO Claude Couty worked on operations, Mariaccia said.

"The silicone gel was made at the factory, at PIP," he said. "It was a 'home-made' gel."

Other workers painted a more menacing picture of operations at PIP.

The false gel had been used since 2001, as PIP bosses were seduced by the price difference between their home-made version and the approved gel, according to an unidentified former PIP executive interviewed for an Aug. 2, 2010 story in Var-Matin.

Reuters was unable to immediately confirm the account given by the Var-Matin source.

Var-Matin quoted the unidentified former PIP executive as saying that while medical silicone gel cost about $60 for 200 kg (441 pounds), PIP's industrial version cost about $10.

Although nobody at the company talked about the two different kinds of silicone being used in the implants, it was obvious by sight, the ex-manager told Var-Matin.

"The medical gel didn't run. By contrast, the 'fake gel' was like soapy water."

PIP was able to continue its ruse because periodic checks by regulators were pre-announced and even suppliers of the industrial oil used to make the silicone were lied to, according to the former executive.

"PIP said that this oil was being used to make hand soap."

Some buyers of the implants, however, were in on the game, Var-Matin quoted the former executive as saying.

"With exports, you'd hear, 'You want a pack of prostheses. Good ones or bad ones?' Everything depended on the relationships we had with the distributors," he said.