Is hard drive data inadmissible?

I handled tech support for all the computers in our home during my marriage. When we seperated, I took all my computer equipment with me. I just found out that I have a clone of my husband’s hard drive, which I made at his request while updating his computer.

He has been hiding assets for years and is not producing documents that I know exist. Can I use the Quickbooks data that I have on the drive as evidence in my divorce? Or is it considered illegal that I have that information?

You can use the evidence as it was stored on a family computer during the marriage, which you had access to.