Sen. Rand Paul (R-KY) has been accused of plagiarising Wikipedia and other sources and the evidence has started disappearing from his official Senate website.

MSNBC Rachel Maddow recently noticed that Paul had taken the exact language from several Wikipedia pages and used it in several of his speeches without proper attribution. And over the weekend, BuzzFeed’s Andrew Kaczynski found that Paul had copied 1,318 words from a 2003 case study by the Heritage Foundation without making it clear that he had not authored the material.

On Monday, Kaczynski pointed out that some of those speech transcripts had been scrubbed from Paul's Senate web page.

In the case of a Feb. 6 speech to the Heritage Foundation, Paul's current page only contains a video, but Google cache shows that the page recently also had the entire transcript.

BuzzFeed found at least three other pages which had transcripts deleted.

Speaking to ABC's George Stephanopoulos on Sunday, Paul admitted that he had made mistakes in citing sources but lashed out at his critics, who he called "hacks and haters."

"I will admit, sometimes we haven’t footnoted things properly," the Kentucky Republican said. "I’ve written scientific papers. I know how to footnote things. But we’ve never footnoted speeches. And if that’s the standard I’m going to be held to, yes, we will change and we will footnote things."

“But the difference is, I take it as an insult and I will not lie down and say people can call me dishonest, misleading or misrepresenting,” he added. “And like I say, if, you know, if dueling were legal in Kentucky, if they keep it up, you know, it would be a duel challenge. But I can’t do that, because I can’t hold office in Kentucky then.”

"I think I’m being unfairly targeted by a bunch of hacks and haters. And I’m just not going to put up with people casting aspersions on my character."