Mohammed Karrar's brother Bassam was also found guilty of rape and conspiracy to rape girls under 13, child prostitution and trafficking.
Fighting broke out in the dock after two of the defendants were cleared.
More top news
The abusive pasts of more than 1,300 violent partners have been disclosed under a scheme introduced less than a year ago, new figures show.
David Cameron has said he wants to cut taxes after the next election because British people "deserve a reward" following years of austerity.
The number of pothole compensation claims is rising and campaigners have urged the Government to pledge more money to fix Britain's roads.