VIENNA: Irregularities could have changed the outcome of Sunday's Turkish referendum which ended in a tight 'Yes' vote for greater presidential powers, Alev Korun, an Austrian member of the Council of Europe observer mission, told ORF radio on Tuesday.
"There is a suspicion that up to 2.5 million votes could have been manipulated, said the Austrian member of parliament.
"This is about the fact that actually the law only allows official voting envelopes. The highest election authority decided however, as it were against the law, that envelopes without official stamp should be admitted," Korun added.
Turkish President Tayyip Erdogan has dismissed criticisms of the vote.
