Britain's Olympic minister said security planning for next summer's Games would not be disrupted by this week's resignations by London's two top policeman over the phone-hacking scandal engulfing the now defunct News of the World.

On Sunday, Britain's most senior policeman Commissioner Paul Stephenson resigned in the face of allegations that police officers had accepted money from the paper and had not done enough to investigate hacking charges that surfaced as far back as 2005.

Within 24 hours, Britain's most senior counter-terrorism officer Assistant Commissioner John Yates also quit, throwing London police into chaos a year before the 2012 Olympics.

Sports and Olympics minister Hugh Robertson told reporters he was "absolutely happy" security planning was where it ought to be and that a new commissioner would not alter plans.

He also said security planners would continue to work towards a severe threat level from international terrorists, despite it being downgraded a notch last week.

"Yes, it is disruptive at the top of the Met, clearly it is, but it is not impacting on the operation of the delivery of security in any way at all," he said during the release of the latest quarterly Olympic financial figures.

Britain has been working on an international terrorist threat level of severe, the second-highest, meaning an attack is highly likely.

The country is facing several potential threats, one of the most high-profile being from al Qaeda after Britain's support of U.S. military operations in Afghanistan and Iraq.

The threat level was reduced this month to substantial, meaning a terrorist attack is a strong possibility and might well occur without further warning.