Does a privilege exist between an accountant and a client? In other words, can an accountant can be called as a witness in cases that involve federal

securities laws, federal mail or wire fraud, or other federal crimes by a client?

Does a privilege exist in federal law? Does a privilege exist in state law?

What has the US Supreme Court held about accountant$-$client privilege?

You may wish to consider the following:

Couch v$.$ U$.$S$.,409$ U$.$S$.322,93$ S$.$ Ct$.611,34$ L$.$ Ed$.2$d $548(1973).$ Cavallaro v$.$ U$.$S$.,284$ F$\mathrm{.}3$d $236,52$ Fed. R$.$ Serv. $3$d $761(1$st Cir. $2002).$

U$.$S$.$ v$.$ Antolini, $271$ Fed. Appx. $268(3$d Cir. $2008).$In re S$3$ Ltd$.,242$ B$.$R$.872($Bankr$.$ E$.$D$.$ Va$.1999).$