Police are to continue the search for a missing Irish tourist on Tuesday after a five hour dive on Sunday gave no result.

Police are to continue to search the same area of water in the Norra Hammarby Hamnen area of Stockholm.

"We broke off the search at 4pm today (Sunday) after having begun at 11am. We will start again in the same area on Tuesday," said police spokesperson Lars Bröns to The Local on Sunday afternoon.

"We are going to get in touch with the coastguard and make use of their Remote Operated Vehicle to assist in the search."

Bröns explained that the police have found no reason to change the focus of their search.

32-year-old John Aherne came to Sweden to celebrate the St. Patrick's weekend with his close friend Karl Lambert.

The two men went out with friends on Saturday night and had a few drinks together at a city centre pub.

When Aherne decided he was ready to go home, Lambert stayed behind and gave his friend a set of spare keys.

"He stopped off at a restaurant on the ground floor of the apartment building," said Lambert, who has spoken to staff at the Orion restaurant on Katarina Bangata in the south of the city.

Aherne had a drink at the restaurant. Leaving his coat on a chair and his phone on the bar, he went outside. He has not been seen since.

"He told a guy in the bar he was just going out for a smoke and would be back in a minute," said Lambert.

Anyone with information relevant to the case is advised to call the police at 114 14.