The father of President Trump’s son-in-law Jared Kushner says the family is not worried about investigations into their company and they have not heard whether special counsel Robert Mueller is investigating their property development business.

“All I know is that we are not at all concerned, and we are cooperating,” Charles Kushner told the Washington Post.

Kushner Companies confirmed last year the U.S. attorney in Brooklyn had subpoenaed information related to the company’s use of a program that allowed foreigners to invest $500,000 to fast-track residency in the U.S. and possible citizenship.

The Kushner family business also handed over documents about a $285 million loan from Deutsche Bank that Jared Kushner acquired just weeks before the presidential election.

“They can knock themselves out for the next 10 years reading those papers as far as I’m concerned,” Charles Kushner told the Post.

He said neither Mueller nor his investigators have given any indication that they’re investigating the Kushner business as congressional officials raise questions about whether Jared Kushner sought Russian financing for 666 Fifth Avenue tower in New York.

“No. Nothing, not heard. If you want to know the truth, no one has contacted us,” Charles Kushner said.

Jared Kushner testified to Congress in July that he did not discuss his family’s company in a December 2016 meeting with a Russian bank executive.