Two northern Ontario women named by Mexican officials in the probe into the February slayings of a Toronto-area couple near Cancun joined Opposition MPs on Wednesday in calling for Ottawa to get more involved in the investigation.

Kimberley Kim and Cheryl Everall of Thunder Bay, Ont., said their lives have been turned upside down since the Mexican head of the investigation into the murders of Domenic and Nancy Ianiero mentioned them as possible suspects. 

"We should not sit with the finger of guilt pointed at us for a crime we had nothing to do with," Everall told reporters Wednesday during a news conference in Ottawa.

The women also called for Ottawa to renegotiate a mutual legal assistance treaty that already exists between the U.S. and Mexico.

Everall and Kim were on vacation at the resort when the Woodbridge, Ont., couple were found in their hotel room with their throats slashed on Feb. 20, 2006.

At one point, lead investigator Bello Melchor Rodriguez called them suspects, but later told CBC News in March that the two women were only potential witnesses in the murder.

Liberal MP Dan McTeague, the former parliamentary secretary for Canadians abroad, said Public Safety Minister Stockwell Day has an obligation to clear the names of the two women and convey to Mexican authorities that Canada sees the investigation as far from closed.

"We have a killer or killers on the loose," McTeague said. "He [Day] has to take into consideration what the families are asking for, and that is to clear their name." 

Ken Boshcoff, Liberal MP for Thunder Bay-Rainy River, said Everall and Kim were "innocents now identified possibly for the rest of their lives, their reputations tainted."

Day said Wednesday that negotiations with Mexican officials continue.

Kim also called on Ottawa to issue a temporary advisory on travel to any destination governed under the state of Quintana Roo, including Cancun.

Earlier this week, the Ianiero family's lawyer Edward Greenspan called on Federal Justice Minister Vic Toews to pressure his Mexican counterpart into taking on the case.

Rodriguez, who has given conflicting statements during the 10-month long investigation, caused a stir last week by saying the probe was stalled because authorities in Mexico are waiting for their Canadian counterparts to provide information.