A man has fallen from a bridge over the M61 near junction eight for Chorley.
All road closures have now been lifted.
A police spokesman said: “It is believed that a man has fallen from a bridge over the motorway.”
A motorist who passed the scene this morning said: "The motorway is at a complete standstill. I got on at Chorley going north and the opposite carriageway was completely deserted.
"Then I saw a police roadblock further up and all lanes had been closed."