Police want to hear from anyone who has information about a large pool of human blood discovered in a Wellington pedestrian tunnel last weekend.

Police were called to Coutts St in the suburb of Rongotai at 10.40pm on Sunday after the blood was found.

The scene was cordoned off while police conducted a scene examination.

Detective Senior Sergeant Steve Wescott said testing shows it was human blood but they did not locate anybody in the nearby area.

Police are asking for the public's help to identify anyone who may have been involved.

"If there is a person involved, our priority is to check on their welfare," Wescott said.

Police want to hear from anyone who was in the area near the tunnel, which runs under the Wellington Airport from Coutts St, Rongotai, to Miro St in Miramar, on Sunday prior to 10.40pm.

They were also asking anyone with CCTV or dashcam footage from surrounding areas to contact police.