Passage 10.31.2
ἐς δὲ τὸ αὐτὸ ἐπίτηδες τοῦ Ὀδυσσέως τοὺς ἐχθροὺς ἤγαγεν ὁ Πολύγνωτος· ἀφίκετο δὲ ἐς Ὀδυσσέως δυσμένειαν ὁ τοῦ Ὀιλέως Αἴας, ὅτι τοῖς Ἕλλησιν Ὀδυσσεὺς παρῄνει καταλιθῶσαι τὸν Αἴαντα ἐπὶ τῷ ἐς Κασσάνδραν τολμήματι· Παλαμήδην δὲ ἀποπνιγῆναι προελθόντα ἐπὶ ἰχθύων θήραν, Διομήδην δὲ τὸν ἀποκτείναντα εἶναι καὶ Ὀδυσσέα ἐπιλεξάμενος ἐν ἔπεσιν οἶδα τοῖς Κυπρίοις.
Polygnotus intentionally brought together, in the same place, those who were enemies of Odysseus. Ajax, son of Oileus, incurred Odysseus' hostility because Odysseus had advised the Greeks to stone Ajax for his offense against Cassandra. As for Palamedes, I know from verses in the Cypria that he was drowned while fishing, and that Diomedes was named as his killer along with Odysseus.