A second child advocacy group, Community VOICES, issued a letter Tuesday night also calling for a more thorough investigation of McGee.
"It is your duty and responsibility as an appointed commission to properly screen all potential employees hired under your watch and the protection of citizens should be your No. 1 priority," wrote co-directors Laurie Myers and Sandra DiBacco.
Details of the allegations against McGee emerged immediately after he was hired by the commission May 1, but eight days later, the commission is still being asked to explain why its due diligence amounted to reading newspaper clippings about the case and speaking with officials in the Patrick administration where McGee worked as a key adviser on casinos.
Karen Schwartzman, a spokeswoman for the commission, said commission Chairman Stephen Crosby would have no further comment about McGee's hiring, and McGee, who started Monday, would not be made available to answer questions.
Gov. Deval Patrick's press office did not return a call asking specific questions about the doubt McGee's hiring is causing and the way it was handled by Crosby.
Schwartzman said the controversy is having no impact on commission business.
"The commission had a 2½-hour meeting and conducted 2½ hours of business," she said. "The commission is doing its work."
A comment made by Daniel O'Connell, McGee's former boss in the state Executive Office of Housing and Economic Development, to The Boston Globe that McGee was falsely accused prompted the boy's family to come forward and express outrage.
Crosby also has been criticized by the family for telling the Times last week the allegations had "zero substance." He also told the newspaper two commissioners had reviewed the case by speaking with a Florida prosecutor, Patrick and O'Connell.
Crosby has since denied telling a Times reporter that, but the newspaper stands behind the story.
Crosby stirred things up again Monday, saying that McGee is presumed innocent in a letter to state Rep. Daniel Winslow, R-Norfolk, who sought a stay of McGee's appointment. That comment prompted Tuesday's reaction by Durso and Bernier of MassKids.
"We believe that the presumption of innocence of the alleged abuser and the presumption of truthfulness of the alleged child victim should be equally considered," Bernier said.
A prosecutor deciding not to pursue criminal charges is fairly common, Durso said.
Research shows that only about 1 percent of all sex abuse allegations are false reports, Bernier said.
She referred to testimony made by Suffolk County District Attorney Daniel Conley, who testified at a hearing that of 1,000 cases reported to his office each year, only 200 are prosecuted.
"That does not mean these cases have no validity," Bernier said.
Two law enforcement officials in Florida believed the boy's story, but a prosecutor twice decided not to bring criminal charges, citing the lack of physical evidence.
The family sued in Suffolk Superior Court, and court records show that after Florida was ordered to release records, which included a videotape of the boy's interview with investigators, the case was settled.
"There is no public agency which should say that the presumption of innocence applies in a case like this — that is simply not true," Durso said.
"An individual who is a defendant in a criminal case is entitled to the presumption of innocence. This is not a criminal case."
The commission should have taken the allegation of abuse as seriously as the denial by McGee, Durso said.
In his letter to Winslow, Crosby said the commission does not have the ability to investigate.
Wendy Murphy, the attorney for the boy and his family, said Tuesday the family remains willing to talk with commission members or other investigators as long as it wouldn't violate the confidential agreement. "They have nothing to hide and would speak to anyone," she said. McGee could give them permission to speak about the case, she said.
Meanwhile, state Rep. James Lyons, R-Andover, has called on Crosby to resign, saying the hiring casts "a disturbing shadow over the hiring practices at the Massachusetts Gaming Commission."
Lyons opposed the casino legislation, but said that has nothing to do with why he thinks Crosby should resign.
McGee's hiring gives the impression of "Beacon Hill insider dealing" and that applicants won't undergo thorough background checks, Lyons said.
McGee is on loan from the Patrick administration for four to five months, though he has expressed interest in applying for the permanent job.