David Wolfe, 68, who now lives in Halifax, was not present in Moncton provincial court on Tuesday when a sentencing date was expected to be set on the other three charges against him.
The matter has been adjourned without plea until Feb. 14.
Wolfe may also be sentenced on that day, depending on his plea and whether a victim impact statement is required from the latest alleged victim.
Wolfe previously pleaded guilty to three counts of indecent assault involving young males in the Moncton area between 1964 and 1967.
He was scheduled to be sentenced on Jan. 6, but his defence lawyer was sick and unable to attend court.
Now, a fourth person has come forward, accusing Wolfe of sexually abusing him between 1962 and 1964, at or near Port Elgin.
Codiac Regional RCMP charged Wolfe in 2012 after the first victim, Richard Dutkiewicz, went public with his story.
Dutkiewicz said he was repeatedly assaulted by Wolfe in the mid-1960s, when Wolfe was an assistant scout master. He went to police after he saw an investigative series by CBC News on sexual abuse within Scouts Canada.
Wolfe's two other victims came forward a short time later.
The investigation by CBC-TV's the fifth estate revealed that scout leaders abused about 340 children from the 1940s until present.
It also found that Scouts Canada kept a "confidential list" of pedophiles barred from the organization and had also signed confidentiality agreements with child sex abuse victims.
About two months after the documentary aired, Scouts Canada issued a blanket apology to any former scouts who had been sexually abused by the group's volunteer leaders.
The youth organization also announced it had hired an outside company to review its past records and appointed an expert panel to examine whether its current child protection policies are working.