Responsa על בבא מציעא 115:1

Q. R. Moses, the plaintiff, was not present when the defendants, the Jewish inhabitants of Quedlinburg, took an oath in order to nullify the testimony of R. Moses' single supporting witness; must they take the oath again in the presence of R. Moses?
A. If the oath has been legally administered by a proper person (who is related neither to R. Moses nor to the inhabitants of Quedlinburg) there is no need for another oath.
This Responsum is addressed to R. Shemariah, and is the second communication regarding this case.
SOURCES: Pr. 231; L. 382; Tesh. Maim. to Haflaah, 1. Cf. P. 514; Mord. Ket. 296–7.

Q. R. Moses, the plaintiff, was not present when the defendants, the Jewish inhabitants of Quedlinburg, took an oath in order to nullify the testimony of R. Moses' single supporting witness; must they take the oath again in the presence of R. Moses?
A. If the oath has been legally administered by a proper person (who is related neither to R. Moses nor to the inhabitants of Quedlinburg) there is no need for another oath.
This Responsum is addressed to R. Shemariah, and is the second communication regarding this case.
SOURCES: Pr. 231; L. 382; Tesh. Maim. to Haflaah, 1. Cf. P. 514; Mord. Ket. 296–7.