GREENSBORO, N.C. â€"  Defense lawyers for John Edwards will argue at his trial that many of the secret payments at issue in the criminal case were actually siphoned off by a trusted aide.

The attorneys say in court papers that the aide, Andrew Young, was using much of the nearly $1 million in payments to build an expansive dream home in North Carolina.

Most of the money was provided by 101-year-old Bunny Mellon, an heiress from Virginia. She had offered under-the-table cash to cover Edwards' personal expenses. Prosecutors say it was used to hide Edwards' pregnant mistress, Rielle Hunter, during his 2008 presidential campaign.

Edwards denies knowing about the money. His attorneys say the money was not a political contribution because it was intended to hide Hunter from Edwards' wife, not voters.