Aug 18 (Reuters) - The British government denied on Monday a media report that it had delayed publication of an investigation into Egypt's Muslim Brotherhood because of disagreements among ministers over its findings.

In April Prime Minister David Cameron asked Britain's ambassador to Saudi Arabia to conduct an investigation into the Muslim Brotherhood, including allegations of links to extremism and its impact on British national security.

The Financial Times newspaper, citing official sources, said on Sunday the report had found that the Brotherhood should not be labelled a terrorist organisation and had found little evidence its members were involved in terrorist activities. (http://on.ft.com/Vx26cc)

However, ministers afraid of a backlash from allies in the Middle East have stalled the publication of the report for several weeks, the newspaper added.

"The review into the Muslim Brotherhood hasn't been delayed. The main findings were completed by July, as per the Prime Minister's request, and work is now underway across government to consider the implications of these findings," a government spokeswoman said.

A spokeswoman for the Prime Minister said the government would make the findings public "in due course" but that it had never set out a timeframe for doing so.

The Muslim Brotherhood, once Egypt's oldest, best organised and most successful political movement, has seen hundreds of its members killed and thousands detained since then-army chief Abdel Fattah al-Sisi overthrew elected president and Brotherhood member Mohamed Mursi 13 months ago, following weeks of protest. (Reporting by Karen Rebelo in Bangalore and Kylie MacLellan in London; Editing by Cynthia Osterman and Ralph Boulton)