Qatar...denied it was violating a new labour law by blocking migrants from leaving the country, saying it was committed to enforcing reforms to improve the rights of millions of foreign workers...The Qatari government said in a statement that any suggestion it was not committed to enforcing the reforms or that it was denying the freedom of movement of foreign workers was "false"...Doha's "kafala" sponsorship system - under which migrants cannot change jobs or leave the country without their employer's permission - has come under scrutiny in recent years with allegations that the system amounts to forced labour. Qatar passed a law on Dec. 13 scrapping the need for migrants to get exit permits from employers, and imposing fines on employers who confiscate workers' passports and withhold their salaries. But trade unionists say migrants still require an exit permit from the government - and that more than 200 migrants have been blocked from leaving Qatar since the law was passed..."We have explicitly stated that expatriates would be prevented from leaving Qatar if there is strong evidence that the expatriate has committed fraud or is attempting to evade prosecution for a crime," the government statement said.