The exact reason as to why the deal collapsed is not known, although the Hammers released a statement on Friday which attempted to clear up a number of suggestions.
It read: "Carlton has not asked for a transfer and has remained committed to the club at all times.
"In being given permission to talk to Stoke, the negotiations did not break down as a result of him asking for too much money. He was discussing wage parity with other key players and was well within his right to do so.
"Further, there is no issue in terms of his reported 'injury problems'. An England striker, he played 43 games last season."
The statement added: "Carlton remains part of the West Ham United first-team squad under Sam Allardyce."
Source: Team Talk
Source: Team Talk