The risk of accidents in Norway's oil industry rose last year after reaching record lows in 2014, a survey by the Nordic country's safety watchdog showed on April 28.

"The results are a warning sign. They indicate that something could be about to happen with the safety level," Petroleum Safety Authority (PTIL) chief Anne Myhrvold said in a statement.

The latest survey, which looks at risks of major accidents, spills and injuries, contrasted sharply with the industry's stated efforts to improve its health, safety and environmental records, she added.

With the price of North Sea crude down by around 60% since mid-2014, oil firms on the Norwegian Continental Shelf have cut spending and investments to protect cash reserves.

"Even though we can't point to a direct link between the survey results and the changes that the industry is experiencing now, it is important to see whether the results are temporary or a trend," Myhrvold said.

The Norwegian oil lobby said companies were working to improve safety regardless of how the business cycle develops.

"We take notice of the numbers from this year's report and work systematically to reduce the risk and number of critical events," the Norwegian Oil and Gas Association said in a statement.