CHESTERFIELD, N.H. (MyKeeneNow) State authorities are renewing their call for information as they mark 25 years since the disappearance of Tina Sinclair and her daughter, Bethany, from their West Chesterfield home — a case that remains open and under active investigation.

According to the New Hampshire Attorney General’s Office and State Police, the mother and daughter were last seen together during the weekend of Feb. 3–4, 2001, at their residence on Mountain Road. Tina Sinclair was 34 at the time, and Bethany was 15. Despite multiple searches over the years, investigators have been unable to determine what happened to them or where they went.

Those efforts have included searches of the family’s former property and dive operations in the Connecticut River, officials said. No evidence located during those operations has resolved the case.

The New Hampshire Cold Case Unit continues to investigate the disappearance and is now applying newer forensic and investigative technologies that were not available when the case first began. Authorities say the reexamination of evidence and past leads, combined with advances in technology, may create new opportunities to move the investigation forward.

Senior Assistant Attorney General R. Christopher Knowles, who leads the Cold Case Unit, said investigators believe there are people who may still have relevant information about the events surrounding the disappearance and that the passage of time can change circumstances that once prevented witnesses from coming forward.

Family members of Tina and Bethany Sinclair also issued a statement ahead of the anniversary, noting that while time has passed for many people, the case remains unresolved for those closest to them. The family urged anyone with information — even details that may seem minor — to contact investigators and help bring closure to a case that has remained unsolved for a quarter century.

Authorities emphasized that tips previously withheld or overlooked could now be significant and encouraged anyone with knowledge of the case to come forward.

Information related to the disappearance of Tina and Bethany Sinclair can be reported to the New Hampshire Cold Case Unit at 603-271-2663 or by email at coldcaseunit@dos.nh.gov.