Police release photos of person of interest in Grey Lynn stabbing

Police investigating a double-stabbing at a Grey Lynn dairy want help identifying a second man they think could help.

A mother and son were brutally stabbed at their family dairy on Great North Rd around 7:15pm on Tuesday.

A man jumped over the counter and attacked the man in his 30s - he has four stab wounds, including two to the abdomen.

His lung and small intestine is ruptured, and he could be in hospital up to a month.

An image of the man.
An image of the man. Photo credit: Supplied/police

When the man's 62-year-old mother rushed to help him, she was stabbed in the stomach - though her husband says she is likely to be released from hospital today.

A 16-year-old is police custody, and has also undergone surgery. 

But police believe there may be up to two accomplices - and want to find the man pictured immediately.

Another image of the person.
Another image of the person. Photo credit: Supplied/police

The family has owned the Hylite Dairy 15 years, and say they're still in shock.