Kansas Sen. Pat Roberts has intensified his television advertising ahead of the Republican primary to run a new spot highlighting a state medical board investigation of tea party challenger Milton Wolf.

The new ad began airing statewide Friday as part of what Roberts’ said was a $350,000 push before the Aug. 5 election. Wolf spokesman Ben Hartman called the ad misleading.

The Topeka Capital-Journal reported this week that the medical board is investigating Wolf over his past postings of graphic X-ray images on a personal Facebook page. The newspaper said it received a letter from a board attorney, asking it to share information in its possession about the postings.

Wolf is a Leawood radiologist and acknowledged posting the X-ray images and dark humor commentary in 2010. He apologized publicly.