The plaintiff, a man who has asked that his name not be published, filed a lawsuit last year alleging Furlong sexually abused him while at Immaculata School in Burns Lake, B.C., in 1969 and 1970.
Two women filed similar lawsuits, and in each case Furlong has denied any wrongdoing. The allegations have not been tested in court.
Court documents indicate the man filed a claim for compensation under the Indian residential schools settlement in which he said he attended Lejac Residential School in Fraser Lake from 1966 until 1975.
"That was when I was at Lejac, I was both sexually and physically abused," says the man's settlement application, filed in August 2005.
The document details several alleged sexual assaults at the school in Fraser Lake and later at Prince George College, but there is no mention of Furlong or Immaculata School. Immaculata was considered a day school, not a residential school, and therefore wasn't included in the settlement agreement.
The document says the man attended Lejac from about 1966 until 1975, though a separate document related to the settlement says he attended Lejac until 1972.
The Roman Catholic diocese that ran Immaculata School has previously said in a statement of defence that it could find no records confirming the man attended the school in 1969 and 1970.
Court documents also indicate the man has a criminal record for using a forged cheque. Furlong's lawyer suggests in court documents that the man's criminal record could affect his credibility.
The revelations mark the latest in a list of developments that have raised questions about the lawsuits.
One of the plaintiffs, Beverly Abraham, withdrew her lawsuit during a hearing earlier this month, saying she could no longer handle the stress of the case. Furlong released a letter he received from the RCMP last year in which an investigator said the force found no evidence to support criminal charges related to Abraham.
The diocese has also said it could find no records at the school related to the other plaintiff, Grace West.
The lawyer representing all three plaintiffs, Jason Gratl, withdrew from all three lawsuits, though a trial is still scheduled in March for West and the man.
The Canadian Press has a policy of not naming the victims of alleged sexual assault, however Gratl has said West and Abraham agreed to have their names made public. The unidentified man did not.
Gratl and Furlong's lawyer both declined to comment Tuesday. The male plaintiff could not be reached.
Furlong's lawyers have also complained in court documents about a lack of disclosure of from the plaintiffs.
Allegations related to Furlong's time teaching in northern B.C. first surfaced in 2012, when the Georgia Straight newspaper published an article alleging physical and verbal abuse.
Furlong filed a defamation lawsuit against the newspaper and reporter Laura Robinson, though he later dropped the newspaper as a plaintiff. Robinson, in turn, filed her own defamation lawsuit against Furlong.