The ICC prosecutor on Wednesday gave judges 20 names of "senior political and business leaders" he claims backed deadly violence after Kenya's 2007 presidential election, his office said.

The 20 were associated with the Party of National Unity of President Mwai Kibaki and the Orange Democratic Movement led by Raila Odinga, which was then in opposition, prosecutor Luis Moreno-Ocampo's office said in a statement.

The two sides are now in an uneasy power-sharing government.

They "organised, enticed and/or financed attacks against the civilian population on account of their perceived ethnic and/or political affiliation pursuant to or in furtherance of a state and/or organisational policy," it said.

Moreno-Ocampo filed his list after judges asked him last month for more information on his bid to open an investigation into violence that killed 1,500 people after Odinga accused Kibaki of voter fraud.

"These senior leaders from both PNU and ODM parties were guided by political objectives to retain or gain power," the prosecutor's statement said.

"They utilised their personal, government, business and tribal networks to commit these crimes.

"They implemented their policy with the involvement of a number of state officers and public and private institutions, such as members of the parliament, senior government officers, the police force and youth gangs."

His confidential list contained the names of those "who appear to bear the gravest responsibility for these crimes," said the statement.

The prosecutor in November asked judges to allow a full-scale probe of the violence in which thousands of people were injured and about 300,000 internally displaced, which he claimed were crimes against humanity.

Kenya has yet to act on the recommendation of its own inquiry that a special tribunal be set up to probe the violence.

The ICC, the world's only permanent independent tribunal to try war crimes, crimes against humanity and genocide, can only take cases when countries are unwilling or unable to do so.