In a surprise appearance, Kevin Spacey returns to court on Nantucket for pre-trial hearing in sex assault case The actor is charged with one count of indecent assault and battery.

Actor Kevin Spacey made a surprise appearance on Monday in a Nantucket courtroom for another pretrial hearing in his sexual assault case, at which his defense attorney blasted the accuser and his mother for allegedly deleting exculpatory text exchanges from the son's phone before turning it over to investigators.

Citing a forensic extraction report concerning the alleged victim’s phone recently turned over to the defense, Spacey’s attorney Alan Jackson made the case during an hourlong hearing that the accuser and his mother, former Boston ABC affiliate WCVB anchor Heather Unruh “cleansed” the phone of any information that could help exonerate Spacey before turning it over to police.

“Here’s the revelation: Heather informed investigators that she had gone through the phone to remove anything that she described as [her son’s] 'frat boy activities,'" he charged.

“Are you kidding me?” an incredulous Jackson wondered aloud.

“Heather Unruh [and her son, the alleged victim] both went through the phone and they cleansed it,” Jackson claimed in the dramatic hearing. “They deleted information they didn’t want the police to have. They deleted information they didn’t want us to have.”

“Why does she get to be the gatekeeper? She isn’t and she can’t be.”

A summer night in 2016

The young man making the accusation -- ABC News isn't naming him because he's an alleged victim of sexual assault -- told police that he was working as a busboy at the Club Car bar and restaurant on Nantucket when Spacey came in the night of July 7, 2016, according to court records.

The young man claims Spacey groped him at the Club Car after he told the actor he was 23 -- not 18 -- and the two drank eight to 10 drinks each together. The alleged victim told police he recorded a portion of the alleged groping in a Snapchat video he sent to his girlfriend at the time.

Spacey pleaded not guilty in January to one count of indecent assault and battery, an allegation his attorneys have characterized in court papers as “patently false.”

Cape and Islands Assistant District Attorney Brian Glenny did not address in court on Monday the issues raised by Jackson about texts or other information allegedly being deleted from the phone before it was turned over to authorities, and a civil attorney for the accuser did not immediately respond to calls for comment about Jackson's claims.

A spokeswoman for the district attorney's office also did not immediately respond to an ABC News request for comment.

In court filings released late Monday, prosecutors deny that they withheld anything from the defense or falsely claimed they weren’t in possession of the man’s cell phone. Prosecutors said that they had already agreed to provide the defense a copy of the information they downloaded from the accuser’s phone.

In the Monday court filings, prosecutors described Jackson's allegations that exculpatory texts were deleted from the phone by the accuser and his mother as "unsupported."

"The Commonwealth should not have to even address these unsupported allegations as the Commonwealth has agreed to provide the forensic download" of the accuser's cell phone, prosecutors wrote in Monday's filings.

"Help"

Jackson cited an example of an allegedly partially-deleted series of text exchanges from the night and early morning of the alleged incident.

“At 1:41 a.m. [on July 8, 2016] there was a text, according to the forensic report, that [used the alleged victim’s first name, that urged him] to “leave and go home,” Jackson said in court.

In response, according to Jackson, the alleged victim texted back, “‘Should I, actually?’”

Portions of subsequently-deleted text exchanges cited by Jackson turned up the words “picture” and “help," according to the attorney.

Before "he handed the phone to police, he deleted the entire message except the word 'help'," Jackson contended. "Their extraction report only shows 'help.' That's the kind of cleansing [the accuser] and Heather were undertaking."

Jackson went on to describe the allegedly newly-uncovered text threads as "big, bold, new news."

"It's new to us!" Jackson noted. "It's new to the court. The problem is, it's not new to them," he said, gesturing towards the prosecutor. "They knew since day one and they kept it from us. That is unjustifiable and outrageous. I’ve never seen a government agency protect information and hold back information [like] in this case."

He also asked Nantucket District Court Judge Thomas Barrett to reconsider a ruling in which Barrett denied an earlier defense motion for access to the information on Unruh's phone, saying that "it's unequivocally in the record now that Heather Unruh was actively manipulating evidence" from the phone.

"Heather Unruh is the person who went to the police first," Jackson said. "She's the one that contacted the sheriff out here. She's the one that was in contact with investigators," Jackson said. "She's the one who signed the consent form. She's the one that apparently has a relationship with top executives in the D.A.'s office. I'm entitled to Heather Unruh's phone as well."

Jackson also charged that Glenny -- the prosecutor -- told him earlier on Monday that unidentified members of the district attorney’s office intentionally withheld the information from the phone from defense attorneys and misled defense lawyers about what information prosecutors had from the phone, in order to buy more time to review the contents of the phone.

In response, Glenny described Jackson’s claim about prosecutors misleading defense attorneys as a “misunderstanding,” not an intentionally misleading effort.

“If there was a misunderstanding between the parties, we certainly apologize for it," Glenny told the judge.

Judge Barrett said that he would issue a written ruling on the defense motions this week. He also noted during the hearing that Club Car surveillance video he ordered turned over to the defense last week apparently does not exist.

Spacey's appearance, which was not mandated by the court, came as a surprise to the handful of reporters and onlookers present. The actor arrived at Nantucket's main municipal building in a light gray suit, a light blue collared shirt and a striped blue tie. Beyond whispering to his attorney in court, he didn't speak in court and declined to respond to to reporters' questions outside of court.

"Great lengths"

On Thursday last week, among a series of rulings on motions in the case, Barrett granted access by Spacey's attorneys to six months of the alleged victim's text messages following the alleged incident, and the surveillance video from the Club Car from 5 p.m. July 7, 2016 to 3 a.m. July 8, according to court records. Barrett also denied a defense request for the text messages of the victim’s mother, Heather Unruh herself, during the same time period.

On Friday of last week, defense attorneys charged in a new court filing that the accuser deleted exculpatory text messages from the time surrounding his encounter with Spacey before turning over screenshots of text exchanges to the police -- and charged that the district attorney’s office knew this and “hid” it from the defense until now.

“Clearly, [the accuser] has gone to great lengths to remove text messages that he believes did not fit his narrative,” defense attorney Alan Jackson wrote in the filing. “The prosecution is aware of this and hid that information from the defense.”

A spokeswoman for the district attorney's office issued a statement on Friday afternoon saying that prosecutors were still waiting for a signed protective order from the defense. The statement did not address the claim that Spacey's accuser deleted exculpatory texts.

Defense attorneys are also seeking more communications between members of the alleged victim’s family and local law enforcement officials, after an assistant district attorney reported to his superiors in April that his sister is close friends with the victim’s family.

In an April 4 memo that was turned over to defense attorneys, First Assistant District Attorney Michael Trudeau emailed Cape and Islands District Attorney Michael O’Keefe and First Assistant District Attorney Brian Glenny that he had recently learned that his sister is close to the alleged victim’s family, and the two families used to vacation together.

Trudeau wrote in that memo that his sister has had no contact with the teen’s family since 2017, and it appears he was not aware of the connection until March 17, at which time he sent an email to District Attorney Michael O’Keefe and Glenny to alert them, according to court records.

Defense attorneys are seeking all communication between Trudeau, his sister, the teen’s mother, law enforcement and top officials in the district attorney’s office.

Despite a number of allegations of sexual misconduct by Spacey from multiple men since 2017, the Nantucket case is the only criminal case that has been brought against the two-time Oscar winner.

"Suffering"

At Monday's hearing, Jackson also advocated for a trial date to be set for this summer.

"Mr. Spacey is entitled to his speedy trial," Jackson argued. "Period and amen. What he is suffering -- every day as this is gone on: there are cameras, reporters," Jackson said, placing his hand on Spacey's shoulders. "Every day this goes on without resolution is a day he suffers, is a day he is not getting justice or due process."

"Mr. Spacey cares about this case," Jackson continued. "We do, and we want a trial, and we are ready to go to trial ... We don’t want to wait until October or November. We think we are entitled in 8 weeks. Why won’t it happen judge?"

Barrett responded that any possible trial date wouldn't come until the fall, noting that on the island of Nantucket -- which has a single courtroom -- criminal trials are only conducted every other month.

ABC News' Aaron Katersky contributed to this report.