Prosecutors in Peru are asking a judge to sentence former President Ollanta Humala to 20 years behind bars for his alleged role in Latin America's biggest graft scandal.

Prosecutor German Juarez told a judge Tuesday that evidence shows Humala and his wife were part of a money laundering scheme during his 2006 and 2011 presidential campaigns.

The pair are accused of taking about $3 million from Brazilian construction giant Odebrecht. They dispute the charges.

Juarez asked that Humala's wife, Nadine Heredia, be sentenced to 26 years in jail. She is accused of hiding the origin of the funds.

Odebrecht has admitted to paying $800 million to officials across the region in exchange for public works contracts.

Peru has gone further than any other nation outside Brazil in holding leaders accountable.