WASHINGTON, Oct 10 (Reuters) -

Republican U.S. Senator Marsha Blackburn wants the CEOs of

AT&T ( T ), Verizon and T-Mobile to disclose

whether they received or objected to subpoenas for phone data

from eight U.S. senators related to a probe of the January 6,

2021 Capitol riot, according to letters seen by Reuters on

Friday.

On Monday, Senate Republicans disclosed a 2023 document that

showed the FBI obtained phone data known as "toll records" from

senators' phones, including Blackburn, tied to the U.S. Justice

Department's investigation of the riot.

She wants the telecom companies to answer questions including

whether they provided "the cell phone records of their personal

devices, their official government devices, or both?"

Separately, Republican Senator Bill Hagerty -- who is among the

eight lawmakers whose information was seized -- said he had

written to Verizon seeking answers about the disclosure of his

phone records.

Verizon on Friday told Reuters it had provided the requested

customer information and call records.

"Federal law requires companies like Verizon to respond to

grand jury subpoenas," Verizon said. "We received a valid

subpoena and a court order to keep it confidential. We weren't

told why the information was requested or what the investigation

was about."

Blackburn said all three companies got subpoenas for phone

records related to "time, recipient, duration, and location of

calls placed on our devices from January 4, 2021, to January 7,

2021."

The records were part of special prosecutor Jack Smith's

investigation into President Donald Trump's effort to overturn

his loss of the 2020 election to his Democratic opponent, Joe

Biden.

Trump was charged in the Capitol assault but the case did

not go to trial, having been delayed and buffeted by a series of

legal challenges.

Smith dropped the case after Trump won the 2024 election

against Biden's Vice President Kamala Harris. Smith cited a

longstanding Justice Department policy against prosecuting a

sitting president, but issued a report saying the evidence he

gathered would have been enough to convict Trump at trial.

Federal Communications Commission Chair Brendan Carr said

Friday in an interview he had previously raised concerns about

prior disclosures of lawmaker records. "We will be part of the

effort to get to the bottom of what happened here," Carr said.