Elon Musk has denied a Wall Street Journal report claiming he had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, accusing the outlet of running “hit pieces” on him and Tesla.

Photograph: Jim Watson/AFP/Getty Images

The chief executive of the electric carmaker tweeted on Monday rejecting the claim that he had an affair with Shanahan as “total BS”, adding that he and Brin were still friends.

Citing unidentified sources, the WSJ reported at the weekend that Musk had engaged in a brief affair with Shanahan in December last year. The paper claimed the affair had prompted Brin to file for divorce from Shanahan in January and had ended the tech billionaires’ long friendship.

Musk tweeted that he was at a party with Brin on Sunday and that there was “nothing romantic” between him and Shanahan, a lawyer and research fellow at CodeX, an organisation dedicated to using technology to improve legal processes, based at Stanford University in California. She is also the president of a foundation that focuses on criminal justice reform, reproductive longevity for women and climate science.

In a later tweet to his more than 100 million followers, Musk said he had “lost count” of the number of “hit pieces” about him published by the WSJ. Musk claimed the news organisation had once reported that the FBI was about to arrest him, although a 2018 WSJ article alleging a criminal probe into Tesla does not refer to arrests being planned.

Brin filed for divorce citing “irreconcilable differences,” the Journal said, quoting records it said were filed in Santa Clara County superior court. Brin is a board member at Google’s parent company, Alphabet, and is the world’s eighth richest man with a fortune worth $94.6bn, according to Bloomberg. Musk is the world’s richest man and is worth $242bn.

In its report, the WSJ also said Brin instructed his advisers to sell personal investments in Musk’s companies after he came to know about the affair. The paper said it wasn’t able to determine how large those investments were, nor whether any sales were made.

The WSJ allegation was published as Musk faces a court battle in October over his attempts to terminate his $44bn purchase of Twitter. Twitter wants to force Musk to go ahead with an agreed transaction that values the company at $54.20 per share. Musk walked away from the deal this month, citing concerns over the number of bot accounts on the social media platform.

The Wall Street Journal, Google and Shanahan have been contacted for comment.