Security agents besiege home of former Nigerian presidential adviser accused of corruption

Security agents are besieging the home of Nigeria's former national security adviser, preventing him from leaving the country because he is refusing to answer questions about a $2 billion arms deal.

The Department of State Security said it wasn't illegally blocking the home of Col. Sambo Dasuki despite a court order releasing his seized passport for medical travel.

Family members said he did not fly Wednesday because of a tip-off he would be arrested. They said Dasuki told agents any new charges should be filed in court. State Security said he refuses to appear before a committee investigating the arms deal.

Dasuki has pleaded innocent to laundering $423,000 and illegally possessing a seized arms cache.

Corruption has dogged Nigeria's ability to combat an Islamic uprising that has killed 20,000 people.