In 1983, Mazzeo lost his job as director, was convicted of tax evasion charges, and sent to jail for six months.
Isley was charged with and convicted of tax evasion charges.
He was arrested by Belarusian authorities on tax evasion charges in 2011.
However, they ruled, he could be extradited on the tax evasion charges.
The tax evasion charges were dropped after his death, while other investigations are ongoing.
With his cooperation, federal prosecutors won convictions against four people on tax evasion charges.
Most of the charges were withdrawn last year on a technicality, but a tax evasion charge still stands.
In 1998 he was under federal investigation for money laundering and tax evasion charges.
Those involved were arrested earlier on tax evasion charges.
In 1985 he was acquitted of tax evasion charges.