Police are investigating Twitter messages directed towards Senator Ted Cruz, the Republican who played a prominent role in efforts to derail Obamacare during the shutdown, officials said late Saturday.
Capitol Police in Washington D.C. told NBC News they were looking into Tweets posted on Friday.
It was not immediately clear which messages were being investigated, or what crimes may have been committed.
Sen. Cruz, a favorite of the conservative Tea Party movement, returned home to a rousing welcome in Texas on Saturday, Reuters reported.
Cruz was greeted with an eight-minute standing ovation in an appearance organized by the Texas Federation of Republican Women. People in attendance, many of them wearing red to show their support for keeping Texas a conservative-leaning state, lined up to greet him.
"After two months in Washington, it's great to be back in America," Cruz joked to a crowd of about 750 in packed ballroom in San Antonio, Reuters said.
Reuters contributed to this report.