Mexico’s National Electoral Institute (INE) has closed a five-year investigation into alleged illicit cash contributions to the ruling Morena party, concluding it lacked evidence to impose sanctions on the party, Pío López Obrador or former official David León Romero. In a unanimous decision on 21 August, the institute said it could not verify the origin, amount or destination of money seen in 2020 videos that showed León handing envelopes to López Obrador, brother of former president Andrés Manuel López Obrador. Consejera Carla Humphrey, who led the probe, told the Council General that investigators found no bank records, accounting entries or tax documents linking the cash to Morena’s 2015–18 political activity. The unit had sought information from the financial-intelligence unit, banking regulator and Mexico City’s judicial authority, but several requests were denied, limiting the scope of the inquiry. The case stemmed from complaints filed by opposition parties PAN and PRD after the videos surfaced. The electoral body’s decision aligns with an earlier determination by federal prosecutors not to pursue criminal charges. Opposition representatives criticised the ruling, saying it undermines confidence in campaign-finance oversight, while INE officials called for stronger fiscal-tracking powers to investigate future allegations.