GREENSBORO, N.C. – Opposing lawyers in the John Edwards trial wrangled with a judge over whether to allow testimony about a sex tape of the former presidential candidate and allegations of an affair involving an ex-aide who ended a week on the witness stand Friday.

Edwards is accused of directing a conspiracy to use about $1 million in campaign donors’ payments to help hide his pregnant mistress as he sought the White House in 2008. He denies knowing about the money and has pleaded not guilty.

Former aide and confidant Andrew Young testified this week that he deposited the payments from a wealthy Texas lawyer who served as Edwards’ campaign finance chairman and an elderly heiress into personal accounts controlled by him and his wife. The money was used to help build a $1.5 million North Carolina home; Young, who is testifying under an immunity agreement, said he did not pay income taxes on the money.

Prosecutors objected Friday when a defense lawyer for Edwards asked Young whether he had threatened to release a “private video” to expose Edwards’ affair with Rielle Hunter.

U.S. District Court Judge Catherine C. Eagles instructed Edwards lawyer Abbe Lowell to continue his cross-examination of Young without mentioning the tape.

After conferring with the judge, Lowell said he would wait to potentially discuss the tape when the defense presents its case.

Hunter sued Young in state court two years ago over ownership of the sex tape and other personal items in Young’s possession.

That civil suit was settled this year with an agreement to destroy all copies of the tape, though there are suggestions in court documents that federal investigators may still have a copy.

Defense attorneys had no intention of showing the tape to the jury but wanted to mention it in the context of the allegation that Young threatened to out Edwards’ affair with Hunter in an August 2008 conversation on a dead-end road near Edwards’ Chapel Hill estate.

Confronted with copies of his amended tax returns for 2007 and 2008, Young acknowledged that he had used about $1 million of $1.2 million in the payments from Rachel “Bunny” Mellon and lawyer Fred Baron for himself.

Young also testified he didn’t pay taxes on the money.

In Young’s 2010 tell-all book about the Edwards’ scandal, he wrote that he considered the donors’ payments to be “gifts,” not taxable income.

The distinction is at the heart of the defense strategy that the secret payments were “gifts from friends” intended to hide Edwards’ affair from his cancer-stricken wife, not campaign contributions intended to influence the outcome of the election.

Hunter is expected to testify later in the trial, also with an immunity agreement.

Young’s wife, Cheri, took the stand late Friday and will return on Monday.