The Federal Bureau of Investigation is looking into what Johnson & Johnson knew about the risks of a surgical tool found to spread uterine cancer before withdrawing its version of the device last year, the Wall Street Journal reported.

J&J said in July that it would ask doctors to return the device, called a laparoscopic power morcellator, which is used to treat uterine growths called fibroids.

It is unclear what stage the inquiry is in, the Journal reported, citing three people who have been interviewed. But the agency has interviewed a retired pathologist who spoke to J&J in 2006 about potential problems with morcellators, a doctor who came forward after her own cancer was exacerbated by the tool and a California woman who collected the names of hundreds of patients who may have been harmed by the tool, the newspaper said.

A J&J spokesman said the company has not been contacted by the FBI regarding its Ethicon morcellation devices.

The U.S. Food and Drug Administration tightened its guidelines on the use of a uterine surgical technique in November, saying it has been linked to the spread of a rare type of cancer.

This came after the agency issued an alert in April last year discouraging the use of the devices to remove fibroids, warning that an estimated that 1 in 350 U.S. women who undergo fibroid procedures each year have a form of cancer called uterine sarcoma.

The devices are used to slice fibroid and uterine tissue into small pieces inside the body, allowing it to be removed through a small opening. The procedure is designed to shorten recovery time and reduce wound-site infections.

Yet the technique can cause injury to local tissues and organs and spread unsuspected malignant tissue to places outside the uterus.

UnitedCare, the nation’s largest health insurer, announced in February that it would place stricter controls on its coverage of hysterectomies amid concerns about laparoscopic surgeries and the spread of undetected cancer.

As of April 6, the insurer requires physicians to obtain authorization before carrying out laparoscopic “keyhole” surgeries and the removal of the uterus via the abdomen, and won’t approve coverage unless they are deemed to be medically necessary.

Al Jazeera and Reuters