A candidate for the Missouri House of Representatives has made an initial court appearance on a federal drug charge, accused of attempting to plant cocaine and Adderall on his Republican primary opponent.

Thomas Ross, 37, is charged with conspiracy to distribute a controlled substance. According to court documents, he is accused of asking a campaign manager to place a small amount of cocaine and a prescription amphetamine pill on his opponent, Louise Secker, in the weeks leading up to the August 4 primary election.

Ross, who resides in Joplin, defeated Secker by a narrow margin of a few dozen votes. He did not respond to requests for comment regarding the charge, which was filed Wednesday. The federal public defender's office assigned to his case has not immediately stated how Ross plans to plead.

Missouri Republican Party chairman Peter Kinder has called on Ross to withdraw from the race, describing the circumstances of his arrest as "serious and deeply troubling."

According to a probable cause statement signed by an FBI agent, a former campaign manager for Ross informed law enforcement that Ross had provided him with a black nylon glove containing a small plastic bag of white powder and a pink and white capsule. The former campaign manager stated that Ross instructed him to place the items in Secker's purse or vehicle while Ross was out of state on vacation.

Subsequent testing by law enforcement confirmed the substances to be cocaine and Adderall. The FBI statement also indicated that Ross sent multiple text messages to his campaign staffer concerning "the substance." In one message, Ross expressed hope that "we could make it happen" before Secker attended a Republican women's meeting at a Joplin restaurant in June, which he described as potentially causing "extreme egg on the face."

U.S. Attorney R. Matthew Price stated that voters are entitled to confidence in elections. "Candidates are expected to conduct their campaigns with integrity, honesty, and respect for their opponents," Price said.