Kushner's security clearance at the time was downgraded from top secret to a significantly lower level of access, effectively cutting him off from reviewing some of the nation's most sensitive intelligence.
The president's son-in-law had his temporary clearance revoked in February as the White House changed its security procedures.
The White House defended the drawn-out process, claiming it wasn't unusual with Kushner's complicated financial history and contacts with numerous foreign officials.
Lowell said in an appearance later Wednesday on CNN that Kushner spent nine hours being interviewed by the special counsel in his November and April sessions.
Lowell said that Kushner answered all questions that were asked. It was limited to questions about former White House national security adviser Michael Flynn, who later was charged with lying to the Federal Bureau of Investigation. Like the president, Kushner was previously a wealthy real estate magnate and headed up his family's company.
"With respect to the information about his everlasting safety clearance, as we said earlier than, his utility was correctly submitted, reviewed by profession officers, and went by way of the traditional course of".
Kushner's clearance has been contested over the last few months after he was stripped of his credentials in February.
"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", Lowell said.
Mark Zaid, a national security lawyer, said people who lose their interim security clearances are often able to get them restored after a fuller investigation of the issues that caused concern for security officers.
Kushner was with Trump in New Jersey the weekend before Comey was sacked, and he was among the attendees at a June 2016 meeting at Trump Tower with a Russian lawyer at which the president's oldest son was told he would negative information about Hillary Clinton. Kushner updated the SF-86 forms once more in June to include that meeting.