LIMA (Reuters) - The Peruvian attorney general's office said on Tuesday it was investigating former president Ollanta Humala and his wife for possible money laundering linked to past campaign contributions.

Prosecutors have asked a judge to lift Humala's banking secrecy in Peru and abroad from the year 2009 until now, the attorney general's office said.

A Peruvian prosecutor said earlier this year that the late Venezuelan president, Hugo Chavez, and two Brazilian construction companies may have bankrolled Humala's presidential campaigns before he took office in 2011.

Representatives for Humala and his wife, Nadine Heredia, did not immediately respond to requests for comment. Both have previously denied any wrongdoing linked to party fundraising.

Humala finished his five-year on July 28, ending his right to presidential immunity from investigations. Humala still enjoys immunity from inquiries into activities during his presidency.

Earlier this year prosecutors barred Heredia from leaving Peru as they probed her finances for evidence of undeclared contributions.

(Reporting by Mitra Taj; Editing by Jeffrey Benkoe)