No further explanation was given but Haq, who is Scotland’s all-time leading wicket-taker, posted a race-related tweet after he was not selected for the 148-run defeat to Sri Lanka on Wednesday.
Haq tweeted: “Always tougher when you’re in the minority! #colour #race”, before later deleting the post.
A Cricket Scotland statement read: “Following a breach of Cricket Scotland’s internal code of conduct, international team member Majid Haq is travelling home from the ICC World Cup.
“No further statement will be issued until internal processes have been completed in due course.”
Haq, who was born in Scotland but is of Pakistani descent, has played more than 200 times for Scotland and taken 258 wickets.
The 32-year-old has, however, only managed three wickets in four matches at the World Cup and was replaced against Sri Lanka by fellow off-spinner Michael Leask.
Scotland have lost all five of their group matches so far, leaving the team one more chance to register a win when they face Australia in Hobart on Saturday.
SCOTSMAN TABLET AND MOBILE APPS