The Bradford sisters missing with their nine children were stopped from leaving the UK in March, ITV News has learned.
Their trip to Saudi Arabia was rebooked for May but there is no suggestion they were intending to travel to Syria at that time. Police are now trying to work out when the trip was planned.
The missing Bradford family paid for their flights from Saudi Arabia to Turkey in cash at the last minute, sources have told ITV News.
The three women and nine children travelled on Turkish Airlines flight TK 99, which landed in Istanbul at 7am on Tuesday June 9.
There was no onward Turkish Airlines booking to another destination, ITV News understands.
Earlier today the husbands of the three woman made tearful appeals for their families to return.
Speaking from Pakistan, one of the husbands of the missing Bradford thought to be heading to Syria has told ITV News of his worry.
Here's what we know about the Bradford family of 12 who are feared to be travelling to Syria.