The hole, which is three metres deep, is filled with water and likely caused by a failed stormwater drain, according to NZ Transport Agency Waka Kotahi (NZTA).
In a statement on Sunday, it warned severe congestion is likely to occur throughout Monday due to the sudden closure of the highway near Oropi combined with a lane closure on Totara Street.
Both areas are major routes in and out of the Mount Maunganui area.
NZTA suggested road users avoid travelling, work from home or use alternative transport if they can.
“NZTA contractors are doing all they can to fix the road, including working through the night tonight, but the timeframe for re-opening is still unknown,” the statement said.
“Hewletts Rd eastbound bus lane will be open for all vehicles going toward Maunganui Road to try and help the situation.”
Work on Totara St is expected to be complete by 6am on Wednesday.