Mishnayos Shekalim Perek 8 Mishnah 7

Rabbi Elazar says: Flesh from offerings of the most sacred order that became ritually impure from a primary source of ritual impurity, whether it became so inside the courtyard or outside, is burned outside. Since its ritual impurity is of the most stringent type, it is not to be brought into the courtyard, or allowed to remain there. However, an item that became ritually impure from a secondary source of ritual impurity, whether it became ritually impure outside or inside, is burned inside. Since its ritual impurity is of a lenient type, it can be brought into the courtyard in order to be burned. Rabbi Akiva says: The place of its impurity is where its burning should occur. Therefore, regardless of whether the source is primary or secondary, such flesh is burned wherever it presently is.

רַבִּי אֱלִיעֶזֶר אוֹמֵר, אֶת שֶׁנִּטְמָא בְּאַב הַטֻמְאָה, בֵּין בִּפְנִים בֵּין בַּחוּץ, יִשָּׂרֵף בַּחוּץ. וְאֶת שֶׁנִּטְמָא בִּוְלַד הַטֻמְאָה, בֵּין בִּפְנִים בֵּין בַּחוּץ, יִשָּׂרֵף בִּפְנִים. רַבִּי עֲקִיבָא אוֹמֵר, מְקוֹם טֻמְאָתוֹ שָׁם שְׂרֵפָתוֹ: