Grassley questions 'credibility' of White House review clearing staff in prostitution scandal A top Republican senator is raising doubts about the internal review that apparently cleared all White House staff of wrongdoing in the Colombia prostitution scandal. Sen. Charles Grassley, R-Iowa, told Fox News on Tuesday that he wants an inspector general or some other third party to retrace the White House review, questioning the "credibility" of the assessment conducted by the White House counsel. Press Secretary Jay Carney announced a day earlier that the counsel had determined the White House advance team was not engaged in "any inappropriate conduct" in Colombia. Carney announced the results of the review after initially claiming Friday it would not be necessary. "Maybe they had a chance to talk to everybody, but it seems to me they came to that conclusion very quickly," Grassley said Tuesday. The senator also fired off a letter posing 14 questions to White House Counsel Kathryn Ruemmler. Grassley asked how many people were involved in the "weekend review" and how many hours were spent on it, in addition to questions about what happened in Colombia. Grassley asked whether any White House staff "had overnight guests" in Cartagena and how many were in Colombia before President Obama's arrival. Carney said Tuesday he hasn't seen Grassley's letter, but added there is no "credible" or "specific" allegation of misconduct by anyone on the White House advance team or staff. The White House announced the results of the internal review as the number of Secret Service agents and military members involved continued to grow. A senior U.S. defense official confirmed Monday that one more military member is now under investigation, bringing the total number of U.S. service members implicated to 12 -- the latest individual was assigned to the White House communications team, though apparently not part of the White House staff itself. Carney said Monday that the White House counsel conducted the internal review as a matter of "due diligence." As many as a dozen Secret Service agents, in addition to the U.S. military personnel, have been implicated in the scandal. At least some of those involved allegedly brought prostitutes to their hotel rooms in Cartagena in advance of Obama's visit -- hotel staff and others apparently were alerted to the behavior after one of the prostitutes complained she was not properly paid.