However, the e-mail reportedly advises that "administrative charges" must be paid before funds are released.
Wisner said families should be aware that no fee should ever be required to access legitimate compensation and that they should "seek professional and experienced aviation counsel to protect their rights."
He recently revealed that he had spoken to families of passengers who were forming a "families association" to present a united front and discuss their claims as a group.
Flight MH370, with 227 passengers, including two infants, and 12 crew vanished en route from Kuala Lumpur to Beijing, about an hour after taking off from the KL International Airport in Sepang on March 8.