Updated at 5:24 p.m. ET
Opponents of special counsel Robert Mueller ramped up their attacks over the weekend with a new claim that he improperly collected thousands of emails from President Trump's transition team and is using them as an illegitimate basis for much of his investigation.
Mueller's office said his team has obtained all the evidence it's using in its investigation properly. And Deputy Attorney General Rod Rosenstein, who appointed him, told Congress last week that he monitors Mueller's operation closely and has seen nothing improper.