Jerusalem Talmud Bava Batra 3.6

משנה: שְׁנַיִם מְעִידִין אוֹתוֹ שֶׁאֲכָלָהּ שָׁלֹשׁ שָׁנִים וְנִמְצְאוּ זוֹמְמְין מְשַׁלְּמִין לוֹ אֶת הַכֹּל. שְׁנַיִם בָּרִאשׁוֹנָה וּשְׁנַיִם בַּשְּׁנִיָיה וּשְׁנַיִם בַּשְׁלִישִית מְשַׁלְּמִין בֵּינֵיהֶם. שְׁלֹשָׁה אַחִים וְאֶחָד מִצְטָרֵף עִמָּהֶן הֲרֵי אֵילּוּ שָׁלֹשׁ עֵדִיּוֹת וְהֵן עֵדוּת אַחַת.

MISHNAH: Two testify for him that he ate its yield for three years; if they are found perjured they pay everything to him. Two for the first [year], two for the second, two for the third, pay together. Three brothers and another joins them; these are three testimonies which count as one testimony.

הלכה: שְׁנַיִם מְעִידִין אוֹתוֹ כול׳. אָמַר לוֹ. מָה אַתָּה עוֹשֶׂה בְתוֹךְ שֶׁלִּי. שֶׁיֵּשׁ לִי בָהּ שְׁנֵי חֲזָקָה. וְהָלַךְ וְהֵבִיא עֵדִים שֶׁיֵּשׁ לוֹ בָהּ שְׁנֵי חֲזָקָה. וְהָלַךְ זֶה וְהוּזְמוּ עֵדָיו. הֲרֵי זֶה נוֹתֵן לוֹ הַשָּׂדֶה וְאוֹכֶל פֵּירוֹת שֶׁלְּג̇ שָׁנִים.

HALAKHAH: “Two testify for him,” etc. One said to another “what are you doing in my field?” “For I have the years of undisturbed possession of it.” He went and brought witnesses that he had the years of undisturbed possession of it. The first one went and proved the witnesses of the second perjured. He has to give him the field and the yield of three years.

אָמַר רִבִּי זֵירָא. הָדָא אָמְרָה. עֵד זוֹמֵם אֵין נִפְסַל בְּבֵית דִּין.

Rebbi Ze‘ira said, this implies that the perjurer is not disqualified by the court.