A man stabbed outside an top central Auckland hotel asked nearby construction workers for help before he died, it was reported.

The man, reported by TV3 to have been 45, who was carrying a briefcase, was stabbed on Thursday outside the Stamford Plaza Hotel in central Auckland.

Covered in blood, he staggered to nearby construction workers asking for their help before a passing doctor gave him medical attention, One News reported.

A man in his 20s fled the scene, but was caught by several pursuers, TV3 said.

An onlooker said the scene was so horrendous they thought the dead man must have fallen from a building.

Police are investigating whether an earlier incident involving an argument with a woman was related to the stabbing.

The woman reportedly made her way into the Stamford Plaza, leaving a trail of blood.

Distraught relatives or friends of the dead man were being kept away from the site of the killing by police, who have cordoned off Mills Lane near the hotel.