(Bloomberg) — U.S. aviation and congressional officials are investigating allegations by about a dozen whistleblowers that there are safety issues with Boeing Co.’s 737 Max aircraft, the Wall Street Journal reported, citing unidentified government employees familiar with the matter.

Some of the claims relate to the design of a suspect flight-control feature or operation of specific sensors that are key to fatal crashes of two 737 Max jets, according to the report.

The allegations were made by Federal Aviation Administration staff and current and former Boeing employees, whose identities are confidential, the officials told the Journal. No details of the allegations have been made public, the Journal said.

Two phone calls to Boeing media relations team from Bloomberg outside the regular business hours went unanswered.

To contact the reporter on this story: Jim Jia in Sydney at jjia1@bloomberg.net

To contact the editors responsible for this story: Shamim Adam at sadam2@bloomberg.net, Stanley James, John McCluskey

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