A Vineyard Haven man who has worked as an assistant boys’ basketball coach at the Edgartown School and volunteered at Martha’s Vineyard Boys’ and Girls’ Club was arraigned Thursday on charges of sexually assaulting a seven-year-old boy.

School officials said the alleged victim is not a student at the school, but Daniel P. Parker’s arrest by Tisbury police on Wednesday prompted the Vineyard schools superintendent to bar him from all Island schools.

Not guilty pleas were entered in Edgartown district court for Mr. Parker, 59, a resident of Vineyard Haven, on three counts of indecent assault and battery on a child under 14. A pretrial hearing has been set for Feb. 27.

He remained free on $5,000 bail, but the Hon. H. Gregory Williams barred him from any unsupervised contact with children and continued an order that he stay away from the alleged victim and the boy’s Island residence.

The boy told police he was assaulted in his bedroom, in Mr. Parker’s truck and in Mr. Parker’s home.

Edgartown School principal John W. Stevens sent a letter to parents on Wednesday, informing them of the arrest and that Mr. Parker was no longer associated with the school. “To our knowledge, nothing inappropriate has taken place involving this individual at our school,” Mr. Stevens wrote.

“We are treating this unsettling arrest with the utmost seriousness and attention,” he also wrote. “We are working closely with the Edgartown police department to ensure the safety and security of our students.”

A check done on all school employees had revealed nothing in Mr. Parker’s background that was troubling, Mr. Stevens said in the letter. Counseling will be made available to anyone in the school who requests it, Mr. Stevens said.

Mr. Parker also volunteered for basketball programs at the Boys’ and Girls’ Club in Edgartown, but in a statement issued yesterday, club executive director Peter Lambos said his access had been revoked.

“The alleged incidents did not take place at the Martha’s Vineyard Boys’ and Girls’ Club, or during any club-sanctioned activity,” Mr. Lambos said in the statement. “At this time, we have no reason to believe that the individual has committed any wrongdoing at the club.”

The statement said Mr. Parker was involved in basketball activities “which were supervised by the club’s staff, and was at no time in the presence of club members without the club’s staff present.” He also had passed a background check, the club said.

In an application for criminal complaints, Tisbury police said the boy complained to a neighbor late last month about Mr. Parker, who was identified as “an informal caretaker.” Mr. Parker had occasional, unsupervised access to the boy “for mentoring sessions” since last September, said the application, which contained allegations that he had fondled the boy on three occasions.

Outside the courthouse yesterday, Mr. Parker declined comment. His wife Jill added: “Only that Dan is absolutely innocent.”

The boy, accompanied by his guardian and a neighbor, came to Tisbury police on Jan. 26. Earlier that day, the boy had told one of the adults “that he is sick of Dan touching him and he doesn’t want him to touch him anymore,” according to a report by Tisbury acting Sgt. Christopher Habekost.

The boy’s neighbor told police she had looked outside her window Jan. 22 and saw Mr. Parker in the front seat of his truck appearing to be “over” the boy, she said. As she walked outside, she said it looked as though his hands were inside the boy’s pants, the report said.

Police telephoned Mr. Parker on Monday to inform him of the investigation involving him and a child and invited him to the police station for an interview. He responded that “someone is trying to defame me!” police said. During that same call, police said Mr. Parker was advised to stay away from the Edgartown School and the Boys’ and Girls’ Club.

At the police station, Mr. Parker was asked “if there was any child who would have any reason to accuse him of inappropriate contact with that child and he answered no,” according to the report. Asked whether any adults had reason “to suspect that he had inappropriate contact with any child and he again answered no.”

The next day, the boy was interviewed in Barnstable at Children’s Cove of the Cape and Islands Child Advocacy Center, which assists law enforcement with sexual abuse investigations, said Tisbury police Det. Mark Santon.

Reached by telephone yesterday, Mr. Stevens, the Edgartown principal, said Mr. Parker had worked for about seven years at the school in a part-time, paid position. He had coached the boys’ junior varsity squad and had “generally good rapport with parents and players and other coaches,” Mr. Stevens said.

His letter to parents of junior high students was e-mailed on Wednesday afternoon and translated into Portuguese for several families. It was also sent by regular mail.

Mr. Stevens’s letter and Mr. Lambos urged parents with any information or concerns to call Edgartown police Sgt. Craig Edwards at 508-627-4343, extension 12.