Ms Satchwell disappeared from her home in 2017 and was last seen by her husband, Richard.
This latest discovery was made on the property where she lived in Youghal, Co Cork.
The remains have not been identified but are being sent to Cork University Hospital for analysis.
Sniffer dogs are reported to have been used in the search, which focused on a drainage area.
State Pathologist Dr Margaret Bolster and a forensic anthropologist, Dr Laureen Buckley, are present on the site today as Gardaí continue their extensive excavation of the property.
Gardaí upgraded their probe into Ms Satchwell’s disappearance to a murder investigation after “significant new intelligence” was brought forward.
A man (50s) was arrested on Monday on suspicion of her murder and was subsequently released without charge from Cobh Garda Station after questioning.
A file is being prepared and will be forwarded to the DPP.
Gardaí have appealed for anyone with information that may aid their investigation to contact them:
"We continue to appeal for any person who may have information relevant to the investigation to contact Midleton Garda Station on (021) 462 1550, the Garda Confidential Line on (1800) 666111 or any garda station.”
