Report states that Tesla requested the dismissal of the attorney who worked on the investigation of Elon Musk at the SEC.

• Tesla's lawyer demanded that a law firm dismiss one of its attorneys or risk losing Tesla's business, according to The Wall Street Journal.
• A lawyer from Cooley LLP was involved in a probe of Tesla CEO Elon Musk, which resulted in a $20 million fine and Musk's removal as Tesla chairman.
• According to the Journal, SpaceX, the rocket company founded by Tesla and Musk, began reducing their collaboration with Cooley LLP in December.

The electric automaker led by Elon Musk's law firm was asked by a lawyer to fire one of its attorneys or risk losing its work with the automaker, according to a report in The Wall Street Journal on Saturday.

The lawyer that Tesla wanted Cooley LLP to fire previously worked at the U.S. Securities and Exchange Commission and interviewed Musk in the agency's probe into the Tesla CEO's 2018 claim that he obtained funding to take Tesla private. The investigation led to a settlement under which Musk and Tesla agreed to pay a $20 million fine each and Musk agreed to step down for three years as Tesla chairman.

Last year, Tesla's lawyer requested that Cooley dismiss the attorney who worked on the SEC investigation, according to the Journal, citing sources familiar with the matter. Despite this request, the firm did not terminate the associate.

Since December, the Journal reports that Tesla has opted to replace Cooley or hire additional lawyers for various cases.

According to the Journal, SpaceX, the rocket company founded by Elon Musk, has ceased to collaborate with the law firm on regulatory matters, as reported by people familiar with the matter.

Tesla has a connection to the SEC through its hiring of David Misler, a former trial attorney for the agency, as a managing counsel.

The National Highway Traffic Safety Administration has probed whether Tesla's Autopilot driver assistance system contributed to crashes involving Tesla cars hitting parked first responder vehicles.

The probe hired Missy Cummings, a Duke University professor, automated systems expert, former Navy fighter pilot, and Tesla critic, as an advisor. In October, Musk tweeted that her track record was biased against Tesla, which led to a backlash from his followers.

The Journal reported Saturday that the NHTSA later mandated Cummings to withdraw from Tesla-related issues.

CNBC did not receive immediate responses from Tesla, SpaceX, and Cooley when requested for comment.

Read the full Journal report here.

— CNBC’s Lora Kolodny contributed to this report

Tesla and Musk have reached an agreement to pay a $20 million fine each and for Musk to temporarily step down as Tesla's chairman.