The Los Angeles Times first reported Wednesday night that federal agents obtained the cellphone belonging to Burr, indicating a major escalation of the Justice Department investigation into the stock trades.

The newspaper reported that Burr turned over his phone to agents after they served a search warrant at his Washington-area residence, citing a law enforcement official it did not identify…

Burr, who chairs the Senate Intelligence Committee, faced calls to resign in March after reports that he privately warned well-connected donors of the dire impacts of the coronavirus pandemic in February while selling off up to $1.6 million of his own stocks.

Burr said in March that he relied on public news reports, not inside information from his role on the Senate committee.