Homeland Security Committee Chairman Ron Johnson asked that DOJ inspector general Michael Horowitz to investigate the matter and whether any wrongdoing occurred.
The Justice Department told CNN it was reviewing Grassley’s letter. A representative for Mueller declined to comment.
CNN has reached out to Weissmann for comment.
Other users whose phones were marked as “wiped” include James Quarles, Rush Atkinson and Greg Andres. (The names of many of those with wiped phones are redacted.)
President Donald Trump and his supporters have long sought to discredit the FBI’s Russia probe and Mueller’s findings, questioning whether the FBI even had reason to open an investigation into his presidential campaign.
The FBI in July 2016 launched a counterintelligence investigation into Russian interference in the 2016 election and possible links between the Kremlin and Trump campaign officials. Mueller took over the investigation in 2017 when he was appointed special counsel.
At Barr’s direction, the Justice Department launched an investigation last year into the origins of the FBI Russia probe.
Barr disputed Horowitz’s finding that the FBI properly opened a full investigation, called Crossfire Hurricane, based on the evidence it had.
Trump and Republicans have also pointed to text messages between former FBI employees Peter Strzok and Lisa Page to argue that an anti-Trump bias exists at the bureau.
Horowitz in his report said Strzok and Page did not affect the start of the investigation or didn’t act out of political bias.
This story has been updated with additional developments.
CNN’s Evan Perez contributed to this report.