Lincoln County District Attorney Bernice Barnett said in a brief statement that, "Divers searching an area of Yaquina Bay in Newport, Oregon, located the body of a woman and a child."
"The bodies have been tentatively identified as those of Mary Jane Longo and Madison Longo," the statement said.
Thursday's grim discovery, along with the recovery last week of the Longo's two other children from nearby Lint Slough, left only the patriarch of the family, 27-year-old Christian Longo, still missing.
The Longo family had been the subject of a nationwide "attempt to locate" bulletin sent to law enforcement agencies by a task force of state police, FBI agents and Lincoln County investigators who have been seeking them since the day before Christmas.
It still was not known Thursday evening whether Christian Longo was alive and whether he had caused the deaths of his 35-year-old wife and their three children.
The identification last weekend of the two children found dead in Lint Slough partially cleared up a tragic pre-Christmas murder mystery in the small, bucolic coastal town of Waldport, about 15 miles south of Newport. The cause of their deaths has not been released, but officials have indicated they did not accidentally drown.
The deaths of Zachary Longo, 5, and Sadie Ann Longo, 3, are being treated as homicides. It is not known if their parents were responsible or if the entire family met with foul play. Photographs of the missing family, which had moved to Oregon from the Midwest in September, were released Thursday.
A van the Longos were using -- which apparently was stolen in the Toledo, Ohio, area two years ago -- was found abandoned at an area car dealership last week, and authorities were still searching for a green Dodge Durango with Michigan license plates that Longo may be driving.
Detectives also collected unspecified evidence at a motel room in Newport where the family had last stayed.
"A search warrant was executed at the Longo residence in Newport," Barnett said in a statement issued earlier Thursday. "Information obtained from that search warrant will be evaluated by the Oregon State Police crime lab."
The Longos reportedly quietly moved out of Ypsilanti, Mich., this year after Christian Longo had been placed on probation for forgery and passing bad checks. Following a brief stay in Toledo, the family headed for Waldport in September. The Oregonian newspaper reported Thursday that the family rented a beach house north of Waldport for about a month before relocating to a motel in Newport in early October.
"When they came in, they seemed like the every-day average family," Clarice Weathers, who rented the home to the Longos, told the newspaper. "They were exhausted and weary from traveling. They seemed very nice, outgoing and friendly."
Mary Jane Longo's mother in Trinity, Ala., told the Oregonian that she last heard from her daughter six months ago.
"Mary Jane never said anything negative about her husband," Susan Lowery said of her daughter. "Chris has never shown any meanness or anything like that."
(Reported by Hil Anderson in Los Angeles.)