House Majority Whip James Clyburn (D-S.C.) on Tuesday blamed balloting machines for an unknown Democrat’s Senate primary victory last week.

"There was something wrong with those machines," Clyburn told the hosts during an appearance Tuesday on MSNBC's "Morning Joe."

Clyburn previously suggested Republicans were to blame, stating that Democratic Senate nominee Alvin Greene was a "plant."

"I don't know if he was a Republican plant; he was someone's plant," Clyburn said during an appearance on the Bill Press radio show last week.

He reiterated his comments Tuesday during an appearance on Fox News.

"He was someone's plant," he said. "I do believe that very sincerely."

He again called for an investigation.

The accusation of ballot tampering comes in addition to Clyburn and others' concerns over whether Greene received his $10,400 filing fee from outside sources, a claim Greene has denied.

"I saved the money from the Army," the veteran told the Washington Post.

Greene won the June 8 primary with 58 percent of the vote, defeating Vic Rawl, a Charleston County councilman, by more than 30,000 votes.

On Tuesday, Clyburn said the machines, which were used in 300 precincts statewide for last Tuesday's primary, had been purchased secondhand from "Louisiana, of all places."

They're the same machines, he said, that Ohio refused to use in past election cycles "after they tested them extensively and found the results to be unreliable."

Clyburn also said the machines were easily hacked.

He stopped short of accusing state Republicans of having tampered with the machines, saying only that "outside parties" were likely involved.

Clyburn also debuted a new, softer tone when talking about Greene than he had previously used — even suggesting he would help his campaign.

The majority whip said he knows Greene's family personally, and he praised some of its members as "retired educators."

He went on to say he wants to make sure that Greene and his family "have what they need."

--Christina Wilkie contributed to this post.