Police hope "innovative DNA techniques" could help identify a newborn baby, whose body was found at a recycling centre a year ago.
The girl, thought to be less than 48 hours old, was found by staff at the Sackers facility in Needham Market, Suffolk, on 14 May 2020.
Officers still don't know her identity, that of her parents or how she died.
Suffolk Police said: "We're still urging anyone with information to come forward. It isn't too late."
The baby girl was found at the plant just after 15:00 BST.
Officers believe her body was transported there on one of two lorries that had collected waste from commercial bins in 52 locations, mainly in the Ipswich area.
"Today marks a year since the body of a newborn baby girl was tragically found at the recycling centre," Ch Supt Tonya Antonis said.
"Since discovering her, we have carried out extensive enquiries and are still working towards understanding the circumstances that led to the little girl being placed in one of two bin lorries and being taken to Sackers."
Officers have trawled through more than 11,000 hours of CCTV footage and visited more than 800 addresses since the discovery.
Forensic analysis of items found at the recycling centre failed to provide any clues about the baby or her parents.
A post-mortem examination provisionally recorded the cause of death as "undetermined", although "a final comprehensive report remains outstanding, owing to the involvement of several experts", police said.
However, officers were now "focussing on the use of modern and innovative DNA techniques to help identity the baby's parents or relatives".
"This baby was found during the first lockdown in the country, a time when her mother may have been in contact with fewer people than normal," Ch Supt Antonis said.
"We're directly appealing to anyone who may have noticed a difference with a female or family member after lockdown eased in June."
She added: "Despite the length of time, we're still urging anyone with information to come forward. It isn't too late, we still need the help of the public.
"We believe someone out there will have crucial information that will lead to us being able to give this baby girl her identity."