The government has been accused of double standards for using a "dangerous loophole" to allow British arms manufacturers to sell weapons to "repressive" regimes around the world.
Charity Oxfam says the defence industry is exploiting lax controls in the export of weapons components to surmount international arms embargoes in their report entitled "Lock, Stock and Barrel".
Oxfam says the defence industry sells weapon components to countries such as Zimbabwe, Israel, Indonesia, Uganda, Nepal, Colombia and the Philippines - rather than selling "complete weapons systems".
But the it adds that components can easily be made up to complete systems once shipped.
Today's report warns there has been an eleven-fold increase in the number of weapons components licensed for export in recent years.
UK foreign secretary Jack Straw appears before a Commons select committee on arms exports today and will face strong pressure to close the loophole.
Justin Forsyth, Oxfam director of policy, said: "The government has put lives at risk by setting up false and dangerous double standards. Whether a machine gun comes in pieces or ready made the suffering it can cause in the wrong hands is just the same.
"These aren't simply nuts and bolts we're selling, these components include firing mechanisms, bomb making equipment, guidance systems and gun barrels."