a reuters investigation uncovered errors in tax returns filed by the clinton foundation and the clinton health access initiative .
for 3 years , the clinton foundation reported it had received nothing from foreign and u.s. governments - despite receiving millions previously .
it will now refile its tax returns from 2010 , 2011 and 2012 but has not ruled out reviewing tax returns extending back as many as 15 years .
the clinton health access initiative is refiling forms from at least 2 years .
experts said it was not uncommon for charities to have to re-file but said it was unusual that a global charity would have to re-file for multiple years .
republican presidential candidate ted cruz called on the non-profit to return all of the money it received from foreign governments .