A man has drowned after getting into trouble during a late night swim on Auckland's North Shore. 

The victim was with a friend at Lake Pupuke - just behind North Shore Hospital - last night when the incident happened. 

"Around 9.15pm yesterday...two men were swimming at Lake Pupuke when one of them got into difficulty," a police spokeswoman said. 

"Despite efforts from his friend, the man disappeared into the water." 

Emergency services including police, fire crews and St John staff were called to the scene and a search was quickly carried out. 

However, they were unable to find him. 

A witness at the lake last night told the Herald the Police Maritime unit was also out on the water in an inflatable rescue boat. 

Several police officers could be seen gathered at the bank of the lake - some looking into the water. 

Fire and Emergency NZ personnel were also on hand to provide specialist lighting equipment for police officers. 

The Police Dive Squad will head back to the scene today in a bid to find the victim's body. 

Police say the matter will be referred to the Coroner.