The widow of a Staten Island man who died after a police officer apparently used an unauthorized chokehold on him collapsed in tears into the arms of the Rev. Al Sharpton during a rally Saturday morning at his Harlem headquarters.

Esaw Garner had to be ushered off the stage as Sharpton described how her husband, 43-year-old Eric Garner of Port Richmond, died Thursday following a confrontation with police after complaints that he was selling single untaxed cigarettes. Part of the confrontation was captured in video taken by a bystander.

"The issue is not whether one was selling cigarettes," Sharpton said at his National Action Network. "The issue was how an unarmed man was subjected to a chokehold and the result is he is no longer with us."

As Sharpton spoke, Esaw Garner became disconsolate, her tears convulsing into sobs. Her knees buckled and Sharpton grabbed hold of her. She and the dead man's mother, Gwen Carr, also visibly distraught, had to be led away.

Marco CarriĆ³n, an aide to New York City Mayor Bill de Blasio who attended the rally, promised a full investigation. "There was a lot of hurt out there," he said. "We will get the answers."

City Councilwoman Vanessa Gibson, who chairs the Public Safety Committee, vowed to hold an oversight hearing in the next few weeks.

Garner's funeral is to be held at 7 p.m. Wednesday at Bethel Baptist Church, on Bergen Street, in Brooklyn.

NYPD Commissioner William Bratton said that the apparent unauthorized chokehold was used by two officers who were attempting to take Garner into custody after local merchants complained he was taking away their business by selling single untaxed cigarettes, known as "loosies," at a small park across from the Staten Island Ferry terminal.

Police officials have said Garner, who reportedly weighed 350 pounds and was more than 6 feet tall, has a lengthy arrest history, including for selling untaxed cigarettes.

"Chokeholds are prohibited by the New York City Police Department and most departments," Bratton said at a news conference Friday. The commissioner added that "Mr. Garner repeatedly complained of difficulty breathing as the officers wrestled him to the ground."

The mayor, who postponed his family vacation to Italy by one day to deal with the incident, called the death "a terrible tragedy."

De Blasio spoke with Eric Garner's wife and mother by telephone Saturday morning, according to Rachel Noerdlinger, chief of staff to the mayor's wife.

De Blasio spokeswoman Marti Adams said the mayor has also been on the phone discussing the case with community leaders, elected officials, clergy and the NYPD. The De Blasios are scheduled to leave for Italy on Saturday evening, Adams said.

De Blasio and Bratton said that a final determination of any breaking of law or departmental regulations would be made after an investigation by the Staten Island district attorney's office and the police internal affairs unit.

But on Saturday, Sharpton suggested that undue influence by the union representing the officers could undermine an investigation. "I have very serious questions," Sharpton said.

When asked about Sharpton's remarks, Douglas Auer, a spokesman for Staten Island District Attorney Daniel Donovan, did not directly comment.

"My office is working along with the NYPD to do a complete and thorough investigation into the circumstances surrounding Mr. Garner's death," Donovan said in a statement

Bratton said the two officers involved -- whom he identified as eight-year and four-year department veterans -- have been placed on desk duty.

With Robert E. Kessler