Peru’s constitutional court has overturned former President Ollanta Humala’s 15-year prison sentence for corruption, declaring the criminal proceedings against him invalid.

Humala had been convicted of receiving illegal campaign funds from Odebrecht and former Venezuelan leader Hugo Chávez, allegations he denied as political persecution.

He was released from prison in Lima after the court ruling, while his wife Nadine Heredia, who was also convicted, remains abroad after receiving asylum in Brazil.

Humala’s case was part of a wider investigation into the Odebrecht corruption scandal that involved several former Peruvian presidents, the BBC has reported.

The ruling now requires prosecutors to end the case, according to Humala’s legal team.