WASHINGTON (Reuters) - The top U.S. House of Representatives intelligence committee Democrat said on Wednesday he had “grave concerns” about the committee’s ability to conduct a credible investigation after its Republican chairman suggested President Donald Trump’s communications may have been collected during surveillance. “I have expressed my grave concerns with the Chairman that a credible investigation cannot be conducted this way,” U.S. Representative Adam Schiff said in a statement. The House intelligence panel is conducting one of the main congressional investigations of possible ties between Trump associates and Russia during the 2016 U.S. president election. Republican Representative Devin Nunes, the committee’s chairman, announced at a news conference on Wednesday that an anonymous source had provided him with information that communications by associates of Trump’s and possibly Trump’s had been swept up during routine surveillance. 
House Democrat says Republican undermines intel probe