More than £50,000 of donations to a homeless "hero" will be refunded after he admitted stealing from victims of the attack.
The funds were collected for rough sleeper Chris Parker after he claimed to have helped some of those injured in the attack.
Some 3,700 people gave a total of £52,539 in good faith after his story spread around the world.
Parker pleaded guilty on Wednesday to stealing a purse owned by Pauline Healey, who was left seriously injured in the attack, and a mobile phone from a teenage girl involved in the bombing.
He also pleaded guilty to fraud after using a debit card from the stolen purse.
Michael Johns, who started the fundraising appeal, said all the money will be returned to doners.
In a statement on the GoFundMe page, Mr Johns said: "I would like to extend my sympathies to his victims that night and also apologise to them for any distress this campaign may have caused them whilst they continue to recover and grieve."
He added that GoFundMe policy prevents him from giving the funds to any other charity or cause.
The bombing killed 22 and left scores injured on May 22 last year.
Parker was seen in CCTV footage leaning over the body of injured survivor Ms Healey to steal her purse as her 14-year-old granddaughter Sorrell Leczkowski lay dying nearby.
Prosecutors at Manchester Crown Court said it was clear the defendant provided "some limited assistance" but that he also took the opportunity to commit the thefts in the immediate aftermath of the atrocity.
Parker has a string of previous convictions, dating from 2000 to February of last year, including the theft of a purse from a woman and numerous shoplifting and burglary offences.
Judge David Hernandez remanded him in custody for sentence on January 30, adding a custodial sentence was "most likely".