Arthur Ream, 68, is pictured in this undated handout photo obtained by Reuters May 8, 2018. Michigan Department of Corrections/Handout via REUTERS

(Reuters) - Police searched a former farm outside Detroit on Tuesday for the remains of up to six teenage girls missing for decades, believing they may have been killed by a now 68-year-old man serving a life sentence for the murder of another girl, police said.

Investigators were digging in a wooded area where the man, Arthur Ream, led officials 10 years ago to the body of a girl that he was found guilty of murdering, said William Dwyer, commissioner of the Warren Police Department.

Dwyer said information from several people, including Ream, led them to believe that the bodies of four to six teenage girls may be buried there.

It might take “two or three days” to determine if bodies were there, Dwyer said in a Tuesday phone interview.

If their remains are located, Ream could face charges related to their disappearances, Dwyer said. The girls were aged 12 to 17 when they disappeared in the late 1970s and early 1980s.

Ream is already serving a sentence of life in prison without the possibility of parole, Michigan Department of Corrections spokesman Chris Gautz said on Tuesday.