In addition, Kushner was interviewed for a second time last month by the office of special counsel Robert Mueller, who is investigating potential ties between the Trump campaign and Russian Federation.
Lowell told Newsweek that Kushner was one of the first to cooperate in any investigation involving the Trump campaign.
"Since then, he has continued this complete cooperation, providing a large number of documents and sitting for hours of interviews with congressional committees and providing numerous documents and sitting for two interviews with the Office of Special Counsel". Like the president, Kushner was previously a wealthy real estate magnate and headed up his family's company.
Unlike many other staff members, Kushner's permanent security clearance was held up for a year, leading to suggestions that Kushner could be in trouble because of never completely disclosing all his financial dealings with foreign businesses.
Federal Bureau of Investigation background checks for security clearances routinely examine an applicant's financial holdings and foreign contacts.
Kushner obtained his permanent security clearance credentials after a yearlong process of background checks, the New York Times reported, citing a person briefed on the matter.
The granting of the security clearance suggests that investigators' scrutiny of Kushner has decreased significantly.
Kushner will now have access to "top secret" intelligence, including Trump's daily briefing from the CIA.
Kushner had reportedly been working in the White House, on subjects as sensitive as a Middle East peace process, and viewing classified materials on a temporary security clearance as he awaited approval on his background check.
"Having completed all of these processes, he's looking forward to continuing to do the work the president has asked him to do".
Kushner's access was downgraded in February when White House Chief of Staff John Kelly ordered that officials with interim clearances be cut off if they hadn't received permanent clearances.
Initially, Kushner did not list his foreign contacts on the form, though he submitted an addendum indicating he was willing to detail them.
Kushner attended a meeting in June 2016 with a Russian at Trump Tower during the campaign in an attempt to get disparaging information on Hillary Clinton, and he attempted to set up a "back channel" to the Kremlin during the presidential transition.
The resolution of his clearances does not guarantee that Mr. Kushner faces no legal jeopardy.