Progress is being made in the investigation into the unsolved murder of 6-year-old beauty queen JonBenet Ramsey, those briefed on the investigation told ABC News.
JonBenet was killed in her home in Boulder, Colorado, in December 1996.
MORE: JonBenét Ramsey's father says advances in DNA technology can help police solve daughter's 1996 murderA law enforcement official said tips have come in as recently as the last month and are being followed up. Also, the renewed investigative efforts of the Boulder police and partner agencies stand in contrast to years of limited detective work to get to the bottom of the case.
In a statement to ABC News Monday, the FBI's Denver office said it will continue to work with state and local partners on the murder investigation, but noted the local Boulder Police Department remains the lead agency.
In the last years, a multi-disciplinary team of experts has been assembled to go through the remaining evidence and apply the most modern scientific and cold case techniques to try to solve the crime, the sources said. The team has consulted with top experts in their fields, the sources said.
It remains to be seen whether there will ever be enough provable information and evidence to support charges.
MORE: Menendez brothers timeline: From the 1989 murders to their new fight for freedomOn the morning of Dec. 26, 1996, John and Patsy Ramsey woke up to find their daughter missing and a handwritten ransom note left on the stairs. Hours later, John Ramsey discovered his daughter dead in their basement.
JonBenet's autopsy determined she was sexually assaulted and strangled, and her skull was fractured. Unknown DNA was found under her fingernails and in her underwear.
John Ramsey, who is working with Netflix on the new docuseries "Cold Case: Who Killed JonBenet Ramsey?", believes new DNA technology could aid police in re-investigating JonBenet's murder.
John and Patsy Ramsey and their son were cleared as suspects in 2008.