Zimbabwe's constitutional court on Tuesday ruled that a disputed elections which handed Robert Mugabe five more years in power were free and fair, dismissing allegations of vote-rigging.

"The Zimbabwe presidential election held on 31st July, 2013 was in accordance with the laws of Zimbabwe," said Chief Justice Godfrey Chidyausiku. "The said election was free, fair and credible."

Southern African leaders called Sunday for the West to lift sanctions against Zimbabwean President Robert Mugabe and his inner circle as they gave their seal of approval to his victory in disputed elections.

Wrapping up its annual summit, the 15-nation Southern African Development Community called for "the lifting of all forms of sanctions hitherto imposed on Zimbabwe", leveled against the veteran president and blacklisted firms and individuals.

Zimbabwe's government on Sunday denied a report in the British newspaper The Times that it had reached a secret uranium export deal with Iran.

The Times story published Saturday quoted outgoing deputy minister of mines Gift Chimanikire that Zimbabwe signed a deal with Iran to supply the Islamic republic with the raw materials needed to develop a nuclear weapon.

Zimbabwe has signed a secret deal to supply Iran with the raw materials needed to develop a nuclear weapon, in breach of international sanctions, The Times reported on Saturday.

"I have seen [a memorandum of understanding] to export uranium to the Iranians," Zimbabwean Deputy Mining Minister Gift Chimanikire told the British newspaper.

Lawyers for Zimbabwe opposition leader Morgan Tsvangirai's party filed a legal challenge Friday against the outcome of a crunch election which gave veteran President Robert Mugabe another five-year term.

Tsvangirai and his Movement for Democratic Change (MDC) charge in a court appeal that the July 31 vote was a "farce" that was riddled with fraud and should be declared invalid.

A senior Zimbabwean election official said Tuesday he has resigned, just days after a colleague quit over the conduct of the vote that extended President Robert Mugabe's 33-year rule.

"Yes, I have resigned (from the Zimbabwe Election Commission)," law professor Geoff Feltoe told Agence France Presse.

Zimbabwe's 89-year-old Robert Mugabe romped to victory in presidential and parliamentary polls on Saturday, but his longtime foe Morgan Tsvangirai vowed to boycott the government formed by the "fraudulent" vote.

The veteran leader scored another five years in office, extending his 33-year rule with a landslide 61 percent of the vote, against Tsvangirai's 34 percent.

Zimbabwe's Movement for Democratic Change said on Friday it would not recognize the results of disputed elections that look set to hand President Robert Mugabe a landslide victory.

"We resolved to reject the election and its consequences, which include the government that will result," spokesman Douglas Mwonzora told Agence France Presse after a meeting of 13 senior party leaders.

President Robert Mugabe's party has won an overwhelming parliamentary majority in Zimbabwe's disputed elections, according to a tally of official results Friday.

With over 180 seats declared by the Zimbabwe Electoral Commission out of a total of 210 up for grabs, Mugabe's ZANU-PF had an unassailable lead.

Zimbabwe's vote was free and credible, the African Union's chief observer said Friday, despite problems reported over missing ballot papers and large numbers of people being turned away from polling stations.

"This election is free... credible," said former Nigerian president Olusegun Obasanjo, who is heading the AU monitoring mission.