Portland, Maine ? An autopsy showed that the Harvard University graduate student who fell into Portland Harbor and drowned in May just days before his graduation had a blood-alcohol level nearly three times the legal limit to drive in Maine.

The Portland Press Herald reports Thursday that 31-year-old Nathan Bihlmaier had no drugs in his system, but a blood-alcohol level of 0.22 percent.

Authorities have previously called his death an accidental drowning.

Bihlmaier was celebrating his pending graduation when he was asked to leave a waterfront bar for being visibly intoxicated. His body was recovered two days after he went missing.

His wife was expecting their first child.

He was a native of Osborne, and a Kansas University graduate.

Police say criminal charges are unlikely in the case.