The Supreme Committee for Elections said on Monday that claims of absence of full judicial supervision at polling stations in the referendum are nothing but "sheer lies and fabrications."

The Committee asked those with evidence to present it so complaints can be studied and responded to immediately, warning that legal action will be taken against those who challenge the integrity of the referendum without presenting evidence.

Rights groups have called for a rerun of the first round of the referendum on the constitution, citing violations that marred it such as lacking judicial supervision and the impersonation of judges in a number of polling stations.

"We can prove that only judges monitored (the referendum)... it is obvious that judges are the ones who receive the ballots," said committee member Mahmoud Shousha as reported by a local newspaper.

Shousha stressed that it is a crime to challenge the integrity of elections or referendums without evidence.

The first round of a referendum on a draft constitution written by an Islamist-dominated assembly began on Saturday while the second round is scheduled for December 22.

The elections committee has received all ballots from polling stations of the 10 provinces of the first round of the referendum on the draft constitution.

It will announce the official results of the two rounds of the referendum after the second round concludes.