In a radio show appearance Monday, Weiner called Trump's suggestion that Abedin may have shared state secrets with him both "wrong" and "outrageous."
During a campaign event in Massachusetts Friday, Trump said it was likely that Abedin had divulged classified information to Weiner, who is now an adviser for a New Jersey public relations firm.
"Do you think there's even a 5 percent chance that she's not telling Anthony Weiner — now of a public relations firm — what the hell is coming across?" Trump said, while also slamming Weiner as a "perv" and a "sleazebag."
"Do you think there's even a little bit of a chance? I don't think so."
The Clinton campaign also responded forcefully to what it characterized as Trump's "patently false" and "bizarre" attacks.
Weiner, who stepped down from his congressional position after a sexting scandal four years ago, stood by his wife, saying she has served the country well in her role.
"Not only didn't she do that [leak information], but even further, she worked in government for 20 years. She's got a reputation that is completely stellar, and anyone in Washington and anyone in New York who's ever worked for her knows that," he said on the "The Brian Lehrer Show."