The English-language Cambodia Daily quoted the man known as Brother Number Two as saying he will reveal all should he be indicted for the joint UN-Cambodia trials.
On Wednesday, the Extraordinary Chambers in the Courts of Cambodia announced that prosecutors had put forward five names they feel they have evidence against for crimes including genocide, homicide and human rights abuses.
The names remain confidential, but media has speculated they will probably include Nuon Chea, as well as former head of state for the Khmer Rouge's Democratic Kampuchea regime, Khieu Samphan.
The regime's deputy prime minister, Ieng Sary, and his wife Khieu Thirith have also been named as possible candidates despite Ieng Sary having been pardoned by former king Norodom Sihanouk on genocide charges.
Duch, the former head of Khmer Rouge leader Pol Pot's infamous secret prison, S-21, where 14,000 were tortured and either died or taken to be executed, is also expected to stand. He is the only one currently in jail awaiting trial.
"I consider this court a battlefield and I will not allow you to try me easily," the paper quoted Nuon Chea as saying by telephone. "At the tribunal, I will also show who the enemy was, and I will allow all people to know what happened during this regime."
Nuon Chea conceded his name was probably "top of the list" of people to face trial.
Prosecutors warned Friday that more candidates may yet be put forward, although the defence has the right to argue against the nominations.
Up to 2 million Cambodians are believed to have died under the 1975 to 1979 regime, during which the ultra-Maoist nationalists abolished money and markets in a drive to turn the country into an agrarian utopia and many minority groups such as the ethnic Muslim Chams were subjected to wholesale slaughter.
Brother Number One, Pol Pot, died in 1998.//dpa