Less than a year after a jury found New York City's so-called Cannibal Cop Gilberto Valle guilty of plotting to kidnap, torture and cannibalize women, two alleged co-conspirators going on trial this week are expected to mount the same defense.

Valle's trial was among the first in the United States to spotlight a thorny legal issue, drawing the fine line between online fantasy role play and violent criminal conspiracy.

Last spring, Valle's lawyers told jurors that the numerous emails and conversations outlining plans to kidnap and eat women were in fact sexual fetish role-play games - part of a large but little-known online subculture of cannibal fetish enthusiasts.

Prosecutors countered that the detailed kidnap plots targeting real women may have started as fantasy chats but grew into real plans. Valle was convicted, although he is appealing the verdict.

This week, Michael Van Hise, 23, of New Jersey, and Robert Christopher Asch, 62, a former New York City school librarian, will be tried on the same key charge. Van Hise faces a single kidnapping conspiracy count, and Asch faces two. Both men's cases arose from the investigation into Valle.

Attorneys for both defendants said they will advance the same defense as Valle.

"The defense in all these cases is the same for a reason," said Asch's attorney, Brian Waller. "It's true."

A fourth man linked with the group, Richard Meltz, pleaded guilty last month to two counts of conspiracy in return for a plea deal.

Former sex crimes prosecutors, First Amendment lawyers and sexual behaviorists said Valle's case appears to be the first to center on a suspected conspiracy to commit a violent sexual crime which began on a website for sadistic fantasy role play.

"It's the perfect alibi," former state sex crimes prosecutor Linda Fairstein told Reuters last year.

Defense attorneys say the men were part of a popular and lawful but misunderstood online fantasy role-playing community, and never intended to break the law.

"You draw on your real life to make it as real as possible, but it's fantasy," Van Hise defense attorney Alice Fontier told a judge last year.

Van Hise began cooperating with federal investigators when he was first approached in late 2012, Fontier said. Van Hise then introduced Asch and Meltz to a female undercover federal agent that the trio discussed kidnapping and cannibalizing.

A spokesperson for Manhattan U.S. Attorney Preet Bharara has declined to comment.

(Reporting By Chris Francescani; Editing by Dina Kyriakidou and Gunna Dickson)