Johnson & Johnson’s stock plunged 4.2% on a Friday report that the Justice Department is conducting a criminal investigation into whether the pharma giant misled the public about cancer risks of its talcum powder.

J&J disclosed in February securities filings that it had received subpoenas from the DOJ and the Securities and Exchange Commission about litigation related to alleged asbestos contamination in its baby powder.

But Bloomberg reported on Friday those subpoenas are part of a criminal probe that joins a regulatory investigation and thousands of civil claims by cancer patients that J&J’s baby powder talc caused their disease.

In an email to The Post, J&J countered that “the implication that there has been a new development in this matter is flatly wrong.”

The consumer-products company added that it’s “fully cooperating with the DOJ investigation” and that documents about the subject “have been publicly available for months on our website.”

The DOJ didn’t respond to requests for comment; the SEC had no comment.

J&J, based in New Brunswick, NJ, has long maintained its talc does not cause cancer, citing nearly 40 years of medical studies that clear the product as safe and asbestos-free.

Some lawsuits, however, have turned up decades-old memos expressing fears by company scientists that asbestos found in J&J’s talc was a “severe health hazard” and could lead to legal liabilities.

Indeed, over the past three years, about a dozen juries have awarded more than $5 billion to plaintiffs who blamed their cancers on J&J’s baby powder and former Shower to Shower products — a line of absorbent body powders the company sold to Valeant Pharmaceuticals in 2012.

The juries made the awards after determining the J&J products contained at least trace amounts of asbestos, which is strongly linked to mesothelioma.

J&J’s stock dip on Friday wasn’t as bad as the 11% decline recorded on Dec. 14 — the stock’s sharpest since 2002 — after a Reuters report claimed J&J knew for decades that asbestos was in its baby powder.

But the more recent criminal inquiry is likely to delay settlement of the many civil claims against J&J.

Civil plaintiffs are reluctant to settle, experts said, before knowing whether a criminal investigation will uncover evidence or produce testimony that advances their own cases.