Is this pro-Trump lawyer lying? The National Enquirer's former chief may have the receipts

On Monday, prosecutors in the Manhattan grand jury investigating former President Donald Trump's $130,000 hush payment to adult film star Stormy Daniels called David Pecker, the former publisher of the National Enquirer and a longtime ally of the former president, to the stand.

It's unclear immediately why Pecker, who was instrumental to bringing down Trump's former attorney and fixer Michael Cohen, was called. But, wrote Jordan Rubin for MSNBC.com, a possible reason is to expose false claims by Robert Costello, a Trump-aligned lawyer who testified to the grand jury last week to try to discredit the claims made by Michael Cohen.

"Costello said he told the grand jury that Cohen acted on his own to make the payment, without Trump," wrote Rubin. "It struck me as a somewhat strange point at the time, because even if it’s true, it doesn’t necessarily negate a charge of falsifying business records, if in fact that’s a charge prosecutors are seeking. That’s because such a charge wouldn’t have to hinge on the motive for making the payment but rather the cover-up. So Trump’s knowledge ahead of time is arguably beside the point, at least for that charge."

"Yet, to the extent that the grand jurors are assessing Costello’s credibility generally, they might want to hear from Pecker about whether he has additional testimony that directly contradicts Costello’s," said the report. "One would imagine that Pecker’s direct knowledge of Trump’s role would have been brought before the grand jury the first time he testified. But it’s possible that Costello’s testimony raised specific questions that required recalling Pecker."

Pecker, who received immunity in exchange for his cooperation in the Cohen prosecution, played a role in Trump's prior hush payment schemes, setting up a "catch-and-kill" arrangement for a story on an alleged Trump affair with model and former Playboy Playmate Karen McDougal.

In January, it was reported that Pecker was meeting with New York prosecutors to provide evidence to them in the hush payment case.

ALSO IN THE NEWS: How 'additional charges' may be coming for Trump