China and Ukraine and conducted personal business.
I'm assuming Grassley & Johnson have the evidence you noted would be needed to open such an investigation, Mormad.
Of course, this is just a twitter user's account:
https://twitter.com/RealAlisonPoole/status/1225254421518569472
BREAKING: Sen. Chuck Grassley (R-IA) and Sen. Ron Johnson (R-WI) requesting the travels records for Hunter Biden from the Secret Service. There is now evidence that Hunter Biden used both Air Force One and Two to travel to China and Ukraine and conducted personal business.