Nancy Ianiero and her husband, Dominic, were found murdered at a five-star Cancun-area resort where they were staying.

A lawyer representing the family of an Ontario couple slain at a Cancun-area resort blasted the lead Mexican prosecutor as a "bald-faced liar" concerned only with promoting tourism.

The scathing criticism came in the wake of fresh accusations by Mexican Attorney General Bello Melchor Rodriguez on Monday that the killers of Dominic Ianiero and his wife Nancy are Canadian.

Rodriguez said the prime suspect, a Mexican security guard who vanished after the couple were found lying in their hotel room with their throats slashed on Feb. 20, had been ruled out because of DNA evidence.

Edward Greenspan, a prominent criminal lawyer representing the couple's only son Anthony Ianiero, dismissedthe latest twist in the eight-month long investigation, saying the information about the DNA test was false.

"The attorney general is a bald-faced liar," said Greenspan, adding that hislatest commentsreflected only concern forthe tourism industry."His constant theme is Cancun is safe for Canadians.

"The only people killing Canadians, he says, in the Cancun region, are other Canadians. Mexican people would never kill Canadians. So Canadians bring your Canadian dollars on down to Mexico."

Rodriguez told reporters that the prime suspect, a Mexican security guard, had been ruled out after a DNA test from a hair sample taken from Nancy Ianiero's hand did not match the DNA of the security guard's mother.

The family's lawyer said that's not true at all.

Greenspan said that DNA tests on the hair sample were done immediately after the murder and showed the hair sample to beNancy Ianiero's own hair.

"The hair found in her hand was the hair of Mrs. Nancy Ianiero," he said, adding that he reconfirmed the fact with Mexican police.

Greenspan went on to call Rodriguez a madman whose only agenda is to protect Mexico's reputation, and said he should resign from his role as attorney general.

But he expressed fears that the investigation into the Ianiero murders was in fact unofficially closed months ago.

Greenspan plans to exert more pressure on the Canadian government and police to find, arrest and charge the prime suspect.

He recently won access to a certified copy of the entire Mexican investigative file, which he expects to receive in a month's time.

Once he has his hands on a copy, Greenspan plans to take it to the Canadian police and government.

Foreign Affairs Minister Peter MacKay said he wassurprised by the lawyer's remarks.

"It's not productive or constructive, and it won't help forward the investigation," MacKay said.

The Ianiero case has seen a series of bizarre twists and turns, with Mexican investigators initiallyaccusing two Canadian tourists in the case.

Rodriguez has been outspoken about the case throughout the investigation, but sometimes backtracked shortly after releasing information.