Nora Quoirin, 15, went missing from the Dusan Hotel in Seremban, south of capital Kuala Lumpur, on August 4, reports Efe news.
Negri Sembilan Police Chief Mohamad Mat Yusop said that at 2.30 p.m., a body of a female "with white skin" had been found.
"As of now we cannot confirm who that body is," he said, adding that a forensics and pathology team will determine the identity.
The Lucie Blackman Trust, a British NGO working closely with the family, said on Facebook it could not confirm the body is that of the teenager's, "however it sadly seems likely".
"Investigations are underway to confirm identity and cause of death," the trust added.
On Monday, Quoirin's French father and Irish mother offered a 50,000-ringgit (about $12,000) reward donated by an anonymous Belfast businessman for information leading to her return.
Her parents had previously said Quoirin was born with holoprosencephaly, a disorder which affects brain development, that she "struggles with coordination" and would not have gone anywhere on her own.
Local police have been investigating her disappearance as a missing person's inquiry. However, the Lucie Blackman Trust said last week that "contrary to several reports that police are NOT treating Nora's disappearance as an abduction, the family have been told directly by police that they are treating it as both an abduction and missing persons case".
Hundreds of searchers have been sweeping the nature reserve in Negeri Sembilan, about 60 km south of Kuala Lumpur, where the girl disappeared.
A recording of her mother saying "Nora darling, Nora I love you, Mum is here" has been repeatedly played on loudspeakers into the jungle over the past few days.
( With inputs from IANS )