"My words are taken from 16 to 17 speeches, cut and paste, adding and omitting, a montage," he said, adding that he has asked Palestinian intelligence to analyze the recording.
Abbas' office had no immediate comment.
It is not clear if there will be any political fallout. Previously, Abbas exiled a top aide, Mohammed Dahlan, after he suggested the Palestinian leader's two adult sons profited financially from their father's position.
Palestinian President Mahmoud Abbas (Photo: AP)
Erekat has been a negotiator with Israel and a ubiquitous media spokesman for the Palestinians for two decades, and he is seen as close to Abbas.
Palestinian negotiator Saeb Erekat (Photo: EPA)
The recording was posted on a Palestinian website Wednesday. It lasts three-and-a-half minutes, with a beep or jump at four points, suggesting some cuts.
In the audio, Erekat is heard saying that Abbas should get tougher with Israel, including by trying to brand Israeli Prime Minister Benjamin Netanyahu a war criminal over Israel's settlement construction on war-won lands. It's not clear if the comments were made before the last round of Israeli-Palestinian peace negotiations broke down in April.
The UN General Assembly's recognition of Palestine as a non-member observer state in 2012 has opened up the possibility of the Palestinians requesting membership in international organizations and conventions. One option would be to try to accede to the International Criminal Court and pursue war crimes charges against Israel over settlement building.
Erekat is heard saying in the recording that the time has come for Abbas to act against Netanyahu, referring to the Israeli leader as a "war criminal and a filthy and contemptible person." He says Abbas "wouldn't listen, didn't listen."
As if addressing Abbas, Erekat is heard saying: "They (the Israelis) humiliate you and the Arabs don't believe you." He noted that Abbas has to coordinate with low-level Israeli army officers when he leaves the West Bank.
Erekat says the current Palestinian approach "is useless" and that "there are cards in your hands, make use of them."
Erekat said he spoke to Abbas on Wednesday and Thursday and that the Palestinian leader laughed about the audio, suggesting it would not disrupt their relationship.