CAIRO (AFP) - An Egyptian prosecutor levelled new accusations against ousted president Mohamed Mursi, who already facing trial on other charges, alleging the Islamist had insulted the country's judiciary when he was president, the media reported on Wednesday.

The prosecutor issued a new detention order for Mursi over his comments that judges had rigged a 2005 parliamentary election.

Mursi, who is already being held by the military at an unknown location, refused to cooperate with prosecutors, the official Mena news agency reported.

"The investigative prosecutors accused Mohamed Mursi of insulting the judiciary by accusing 22 judges of forging parliamentary elections in 2005," the agency reported, without providing details.

In 2005, the Muslim Brotherhood was a banned organisation but allowed to run candidates as independents for Parliament under then President Hosni Mubarak, who stepped down in 2011 after a popular uprising.

The Brotherhood won one-fifth of seats in Parliament then, but observers and even one judge who oversaw the vote said the election was partly rigged.

Last week, prosecutors referred Mursi to trial for allegedly inciting the murder of protesters outside his palace in December 2012.

The military overthrew Mursi on July 3 following massive protests demanding his resignation after only a year in office.

The popularly backed coup ushered in a fierce crackdown against his Muslim Brotherhood movement, in which more than 1,000 people have died.