MONTGOMERY COUNTY, Md. (WUSA9) -- Police provided a major update in the Lyon sisters case Friday evening.
A Major Crimes Detective with the Montgomery County Police Department has confirmed to WUSA9 that 58-year-old Lloyd Welch told investigators that he left a shopping mall with the two girls on the day they went missing.
Lloyd Welch also told investigators that he later saw his uncle Richard Welch sexually assaulting one of the girls, according to the detective.
The same detective tells WUSA9 that Welch's statement was "valued and used to further the investigation by being placed in a search warrant."
Another departmental contact declined to comment whether Lloyd's Welch's information helped detectives move the case forward in trying to find the two sisters
Investigation led detectives to Bedford County in Virginia in February 2014. Lloyd Lee Welch, also known as Michael Welch was named a person of interest in the case, authorities said.
PREVIOUS STORY: Person of interest revealed in Lyon sisters' case
Authorities continued the investigation and have been searching for evidence that Llyod Welch and other people, including his uncle may have had a connection with the sisters' disappearance. Police believe family members of Richard and Lloyd Welch may have more information about the incident.
Search warrants have been executed at different residences, according to officials.
The investigation has been ongoing for 40 years after Katherine Lyon, age 10 at the time and Sheila Lyon, age 12 at the time went missing.
We continue to urge anyone with information about this case to call the Montgomery County Police Department-Major Crimes Unit immediately at 240-773-5070.
RELATED STORIES: Police: Multiple people involved in Lyon sisters disappearance