DETROIT — The U.S. government’s road safety agency says it has received allegations that defective Goodyear motor-home tires caused crashes that killed or injured 95 people during the past two decades.

The allegations were revealed in an information-seeking letter dated Tuesday that was sent to Goodyear by the National Highway Traffic Safety Administration. The agency began investigating whether the company’s G159 tires are unsafe last year after a judge ordered the release of Goodyear data that had been sealed under court orders and settlement agreements.

Lawsuits and safety advocates allege the tires were designed for delivery trucks and not for recreational vehicles that travel at highway speeds. They allege that Goodyear kept the tire problems secret for years by settling cases and getting judges to seal records. Despite the allegations, the tires have not been recalled.

In a statement Wednesday night, Goodyear said it received the letter “and will cooperate fully with NHTSA in its investigation, including providing requested information on its G159 tires.”

The investigation covers about 40,000 tires made from 1996 to 2003. In the letter to Akron, Ohio-based Goodyear Tire & Rubber Co., the agency says it has allegations that the tires resulted in two deaths or injury claims in 1998, four more in 1999, six in 2000, eight in 2001, 18 in 2002 and 57 more from 2003 through 2015. The letter did not break down how many of the claims involved deaths, nor did it specify the source of the information.

In a Dec. 28 document that started the investigation, NHTSA said it obtained claim and complaint data about the tires after the court order unsealed the documents and released them to NHTSA.

The nonprofit Center for Auto Safety and Public Justice sought to have the records released to the public, which Goodyear opposed. An Arizona judge ruled in favor of the center on Wednesday, unsealing most of the information. But Jason Levine, the center’s executive director, said the release of the documents was delayed pending an expected appeal from Goodyear.

In his ruling, Maricopa County Superior Court Judge John Hannah wrote that Goodyear’s need to keep information confidential “does not come close” to outweighing the public’s need for access.

“That information — primarily concerning the tire’s design, its testing, the decision to market it for use on motor homes, and the adjustment data generated by consumer experience with it — should be made public because it relates to and reveals a substantial potential risk to public health or safety,” he wrote.

Levine said it would have been better if NHTSA began investigating sooner, “but the real problem here is that Goodyear was using secret settlements for two decades to hide information about these dangerous tires from the government and the public.”

Messages were left seeking comment from NHTSA.

Goodyear spokesman Jim Davis said in a statement that the company continues to believe there is no safety defect with the tires. Goodyear has strong quality controls in place, follows industry standards in manufacturing tires, and monitors their performance in the field, he said.

It’s not known how many G159 RV tires are still in use since production stopped in 2003, the statement said. Anyone who believes they have the tires on a motorhome or has any questions should contact a Goodyear retailer, which will do a free inspection, Davis said.

The letter from NHTSA raises questions about whether Goodyear failed to report all death and injury claims to NHTSA. In the document opening the investigation, NHTSA said Goodyear reported only nine claims alleging one death and 13 injuries. NHTSA wrote in that document that many of the claims were not required to be reported.

Sean Kane, president of Safety Research and Strategies Inc., a Massachusetts firm that does auto testing for plaintiffs’ lawyers and other clients, said that tire makers don’t have to report deaths and injuries involving tires that are more than five years old.

The agency’s letter asks Goodyear for complete claim data and production changes it made with the G159 tires. It also asks Goodyear to describe how it analyzes injury claims to find possible safety defects with its tires. Goodyear has until May 4 to respond but can ask for an extension.