Ashley Key and Britny Haarup were last seen Friday morning.
Updated at 4:50 a.m. ET: Authorities reportedly found the bodies of two women in a rural field in western Missouri on Sunday evening after interrogating a suspect over the disappearance of a young mother and her sister.
The Platte County sheriff's office said it could not immediately confirm the identities or causes of deaths of the women discovered near Trimble, Mo., which is about 30 miles from Kansas City, Mo., the Kansas City Star reported.
"We have one individual in custody and we believe that person accounts for all the individuals involved in the sisters' disappearance," the Star quoted Capt. Erik Holland of the sheriff’s office as saying.
Infant daughters left at home
Britny Haarup, 19, and her sister Ashley Key, 22, have been missing since Friday, when Haarup’s fiancé, Matt Meyers, found her two infant daughters alone at her home.
The sisters also left behind their purses and a cellphone, NBC affiliate KSDK-St. Louis reported. A comforter soaked in blood was also found in the home, and relatives said guns were missing from the dwelling, the Star reported.
The women found in the field were Caucasian, Holland told the Star. "We can say we were led here based on information from a suspect in the disappearance of Britny Haarup and Ashley Key."
"That individual is under arrest and in custody," the newspaper quoted Holland as saying.
"We all had held out hope,” Cassie Meyers, Matt Meyers' sister-in-law, told the Star after the bodies were found. "We were hoping they'd just show up OK, or that they'd call someone. … With this news, even if it isn’t yet confirmed, the hope’s not there."
Earlier, relatives said one of the women had been running with a "bad crowd," KSDK reported.
Britny Haarup "would never go off and leave her children," KSDK quoted Paul Haarup, Britny and Ashley's father, as saying. "So knowing the children were alone, there was something wrong."
The relationship between the suspect in custody and the sisters remained unclear.
NBC News affiliate KSDK contributed to this report.
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