A Lancet paper claims the bank faked figures, boosting the success of its malaria projects, and reneged on a pledge to invest $300-500m in Africa.
It also claims the bank funded obsolete treatments - against expert advice.
The bank has denied the allegations and says it is investing $500m to $1bn (£280m-£560m) over the next five years.
But it also admits it is not easy, and sometimes "not even possible", to know exactly how much input from each donor goes into a specific activity.
Malaria drug is not widely used in poor countries LINK
Part of the problem is lack of a medical infrastructure...another part is lack of money for this more expensive treatement.