By Mike Scarcella and David Thomas

WASHINGTON, Dec 2 (Reuters) - A federal judge on Tuesday referred prominent plaintiffs' law firm Hagens Berman and its managing partner to the U.S. Justice Department for investigation, citing findings of “misconduct bordering on the criminal” in cases it brought over alleged injuries from the drug thalidomide.

U.S. District Judge Paul Diamond in Philadelphia said in his order that a court-appointed official uncovered a decade of alleged wrongdoing in the thalidomide litigation by the firm, managing partner Steve Berman and former partner Tyler Weaver. Diamond's ruling also referred Weaver, now at another firm, to the Justice Department.

Diamond said the lawyers were found to have conducted "grossly inadequate" investigations into the strength of product liability claims against drugmakers Sanofi SASY.PA, GSK GSK.L and Grunenthal, and that the attorneys made "false and baseless allegations" to counter arguments that many of their claims were time-barred.

When confronted, Diamond wrote, the firm allegedly sought to abandon its clients to avoid sanctions.

Berman and his firm have denied any wrongdoing. Berman and an attorney for Weaver did not immediately respond to requests for comment, nor did spokespersons for Sanofi, GSK and Grunenthal.

Hagens Berman has since 2011 represented plaintiffs who claimed major drugmakers concealed the dangers of thalidomide, which pregnant women used to treat morning sickness until its use was discontinued in the 1960s due to birth defects.

The drug companies asked the court to dismiss the cases and sought sanctions against Hagens Berman, arguing that the firm should have known its claims were filed too late. In 2015, Diamond appointed a special master, William Hangley, to interview the firm's clients.

Hangley's October 2023 report recommended sanctions against Hagens Berman over its prosecution of the cases, finding that it failed to vet its claims, obstructed discovery, and that Weaver had doctored a medical expert's report to pressure a client into dropping her claim.

Berman told Reuters in October that his firm has "thoroughly explained why we had a good faith basis" for the litigation. The fact that the case has not succeeded is not a ground for sanctions, he said, adding that personal injury cases "are lost in every court on a finding of a lack of causation or an exclusion of an expert."

The case is Glenda Johnson et al v. SmithKline Beecham Corp et al, U.S. District Court for the Eastern District of Pennsylvania, No. 2:11-cv-05782-PD.

Read more:

Law firm Hagens Berman battles sanctions in Apple, thalidomide cases

(Reporting by Mike Scarcella)

((Email: mike.scarcella@thomsonreuters.com; Phone: 202-985-8228.))