If special counsel Robert Mueller hasn’t talked to the Russian lawyer who met with top Trump campaign officials, it would constitute “dereliction” of duty, attorney Solomon Wisenberg said Monday on “The Laura Ingraham Show.”

Russian lawyer Natalia Veselnitskaya met with President Donald Trump’s son, Donald Trump Jr., son-in-law and senior adviser Jared Kushner, and then-campaign manager Paul Manafort at Trump Tower in June 2016.

Because Veselnitskaya promised to provide dirt on 2016 Democratic presidential nominee Hillary Clinton, many of Trump’s critics cite this meeting as evidence of Russian collusion with Trump campaign members.

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But Veselnitskaya told the Associated Press Sunday that Mueller’s team has not contacted her at all.

“That’s very interesting for someone as thorough as Mueller and the Mueller team,” Wisenberg, former deputy special counsel for Kenneth Starr’s Whitewater-Lewinsky investigation of former President Bill Clinton, told host Laura Ingraham.

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“But you would think [Mueller] would want to talk to her, particularly as she was meeting with the head of Fusion GPS both before and after that meeting at Trump tower,” Wisenberg continued. Fusion GPS is the opposition research firm that was paid by the Clinton campaign and the Democratic National Committee (DNC) for the infamous dossier of “salacious but unverified” allegations of collusion between the Trump campaign and Russian interests.

Although Wisenberg noted that persons of interest in a special counsel’s investigation sometimes make inaccurate claims that the investigator is unable to refute publicly, if the Russian lawyer’s claim is correct, then it is “absolutely striking.”

“But if she is accurate and nobody has even tried to speak to her, that is a striking fact, given that this is one of the more significant meetings that took place with respect to the whole issue of Russian alleged collusion, because some people went to that meeting thinking that they were going to get Russian dirt or information about Russian dirt relating to Hillary Clinton,” Wisenberg said.

“So the idea that she would — that there had not even been an attempt to interview her is absolutely striking,” Wisenberg continued.

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Although Mueller may have been trying to interview the Russian lawyer but ran into “some kind of interference,” Wisenberg said that it would be a “real dereliction” of duty if Mueller “hasn’t made that attempt.”

“The fact is if you’re Mueller and the heart of what you’re investigating is Russian collusion, why haven’t you spoken to her?” Wisenberg said. “It’s just incredible to me — that’s why I say I’d want to check it out because it is incredible to me that [he] would have at least not tried to do that.”

Wisenberg also commented on the FBI’s raid on the home, office, and hotel room of Trump’s personal lawyer, Michael Cohen, earlier in April.

“It’s not that difficult to get a garden-variety search warrant, including a search warrant against an attorney. It’s not that difficult in any district in the country, including the Southern District of New York,” Wisenberg said.

“Now, obviously in this case you would hope the Southern District had very, very solid evidence, given whose attorney they are searching. And you would hope that a magistrate would look at it very carefully,” he said.

“But there is a relatively low legal standard, as you know — it’s probable cause,” Wisenberg told Ingraham.

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Cohen is now under investigation for potential campaign finance law violations and a $130,000 payment to porn star Stormy Daniels, who claims she was silenced during the 2016 presidential campaign after an alleged affair with Trump more than 10 years ago.

“If it’s only a campaign finance violation and alleged bank fraud relating to that, I think there’s going to be tremendous blowback,” Wisenberg said. “They’d better have something considerably more than that.”

Wisenberg also said that “one of the real ironies here” is that many members of Mueller’s team “were seated at a meeting with Trump’s legal team about whether or not he would come talk to them when this story broke.”

“I’m not sure at all that Mueller’s people knew that a search was about to happen,” Wisenberg claimed. “One of the big ironies here is that this could end up very much damaging Mueller’s reputation and the whole investigation. And it’s a gift from the Southern District because they weren’t — they operated in an extremely aggressive manner here.”

PoliZette writer Kathryn Blackhurst can be reached at [email protected]. Follow her on Twitter.