Obaid Humaid Al Tayer told an audience of advertising and media executives that he would have taken ABC UK to court if Gulf News found irregularities with any circulation audit figures.
Gulf News had applied to be audited by both ABC UK and the BPA before the audit firm's decision to quit the Middle East.
"I wonder why all of a sudden ABC decided to withdraw from this market?" he said. "Weren't they up to the challenge, were they fixing the figures, or were they just stamping the figures and collecting the fees?
"I will leave it up to you to decide what happened."
On the same day another rival publication - Emirates Today - was celebrating its first birthday, Gulf News revealed that for the first three months ending March this year it had a total average qualified circulation of 91,985 a day for its Saturday to Thursday editions and 94,247 for its Friday edition.
A breakdown of the BPA figures show the broadsheet had subscriptions sales of 70,125 on Saturday to Thursdays with 69,634 on Friday. Single copy sales for Saturday to Thursday stood at 21,052 and 23,805 on Friday.
Circulation in the UAE stood at 89,004 on Saturday to Thursday and 90,668 on Friday, with international circulation, which includes the Gulf states, India and Pakistan at 2174 and 2771 respectively.
Khaleej Times, which has received its final audit from ABC UK for the six months ending June this year, had a headline total average daily circulation of 69,326, of which 35,153 were from newstrade and single copy sales; 21,476 were subscription copies and bulks which are given away for free or at a reduced cover price accounted for 12,697.