(Corrects to add first name of Musk in fifth paragraph.)

Sept 7 (Reuters) - Former Disney CEO Bob Iger said the entertainment giant had determined that a "substantial portion" of Twitter's users were "not real" in 2016, when it weighed a purchase of the social network.

Iger said the Walt Disney Co and Twitter Inc boards were prepared to enter negotiations when he got cold feet. He said that, with Twitter's help, Disney had learned that a substantial portion - though not a majority - of users were fake.

"I remember discounting the value," as a result, Iger said, in remarks Wednesday at the Code Conference in Beverly Hills. It's not clear what Iger meant by "substantial." Elon Musk, Tesla Inc Chief Executive, has accused Twitter of withholding data on the true number of bot and spam accounts on the platform and is using the issue as his reason for dropping his $44 billion offer to buy the company. Twitter has sued Musk to hold him to the deal, and the trial will begin on Oct. 17.

Twitter did not immediately respond to a request for comment.

(Reporting by Dawn Chmielewski in Beverly Hills, Sheila Dang in Dallas. Editing by Shri Navaratnam)