Mandeep Singh was last seen by his friends at 3am on Sunday after leaving the Bungalow 8 Bar in Viaduct Harbour.

Police are appealing for help in the search for an Indian student who has been missing in Auckland since Sunday morning.

Mandeep Singh, 20, did not arrive home after a night out in the city with friends.

He was last seen by friends at 3am on Sunday after leaving the Bungalow 8 Bar in Viaduct Harbour.

Police would like to hear from anyone who may know of his whereabouts or who may have seen him in the vicinity of Viaduct Harbour in the early hours of Sunday morning.

He was wearing a blue collared shirt, blue jeans and black and white shoes and is described as slim build, with brown hair and brown eyes and around 5'8" tall.

His brother-in-law Aman Narang said relatives in New Zealand were nervously holding hope that Mandeep would be found.

He said he has been relaying all information to Mandeep's parents in India who were "shattered".

The police were keeping them updated, he said, though they could not disclose all information on their investigation.

"We are just waiting to hear. We've been out on all the streets looking for him. Hopefully he can come back to our family. Hopefully he is not in trouble. We can only pray."

Narang said Mandeep moved to Auckland in February and was a hard-working student.

He said he was usually in daily contact with his parents and was close with his flatmates, who he was out with on Saturday night.

Since Sunday morning his phone has been off and no-one has had any contact from him.

"It is very out of character for him. Especially for not calling his mum he usually makes frequent phone calls. And he hardly drinks or goes out like this. It's very unusual."

Singh is enrolled in a culinary arts course at the Cornell Institute of Business and Technology.

A spokesman for the institute said they were still in the process of talking to his classmates and working with the police to find out more information.

Singh also works part-time at Cafe Melba.

Owner Shawn Pope said they were working with authorities.

"Hopefully he's safe. He's a good guy."

One of Singh's flatmates Gurjeed Singh told the New Zealand Herald that he was with Mandeep at Bungalow 8 after their other two flatmates left at about 2am to go to another nightclub.

"He told me to go to the other side and enjoy myself, to go to the dance floor," Gurjeed said.

"I was dancing and enjoying myself. After 20 or 25 minutes I looked for him and he was not there."