SCOTTISH salmon giant Marine Harvest is still waiting for answers over how products labelled with its logo appeared in a smuggling bust in China, a spokesperson said.

Chinese authorities seized fish worth $100 million at the end of last month. The produce is understood to have entered the country through Vietnam.

TV news footage showed boxes of fish bearing the logos of Marine Harvest and competitor Scottish Salmon Farms, both of which are owned by Norwegian operators.

Marine Harvest, which has 49 sea farms on the west coast of Scotland, ended all shipping through Vietnam several years ago and “totally rejects” any suggestion of involvement in black market activities.

Meanwhile, SalMar, which owns Norskott Havbruk AS, the parent company of Scottish Sea Farms, says it has not been approached by any authorities in response to the operation.

Yesterday SalMar appointed a new chief executive officer to replace former post-holder Trond Williksen, who “asked for relief from his position”.

It comes reports in Norwegian title Dagens Naeringsliv that an executive linked to SalMar – a Chinese woman with a Norwegian passport – has been arrested in China in connection with the investigation.

The issue is playing out as First Minister Nicola Sturgeon is in China on a trade mission.

Yesterday the Scottish Government told The National: “We have been following this issue closely and have engaged with relevant partners concerning any suggestion of an illegal trade in Scottish farmed salmon.”

Anti-smuggling raids took place in several locations on March 27 and Zheng Jun, customs deputy director of port city Guangzhou, said some fish seized had come from Norway. Those involved are said to have avoided customs and undercut legal sellers.

A total of 17 people from seven groups were arrested.

Marine Harvest said the issue has not yet damaged its reputation in the key market, but that it is taking the issue seriously and needs answers from authorities.

Last year its farms produced 60,000 tonnes of salmon, six per cent of which was sold to China.

On the news footage, a Scottish spokesman for the company said: “What we don’t know is where the photographs were taken. It could be that the cold storage legitimately had Scottish fish and also held smuggled fish.

“This seems the kind of thing we need to get to the bottom of.”

In February figures released by HMRC revealed Scottish salmon exports had reached their highest ever value, hitting sales of £600 million during 2017 – a 35 per cent jump on the previous year.

As much of £69m of the trade was with China.

Scottish salmon is protected under European law and is celebrated for its provenance and quality.

Marine Harvest said any indication that its name had been used fraudulently would “be a concern”.

The company said: “Scottish salmon carries a PGI (Protected Geographical Indication) status like champagne.

“That standard is very highly regarded in the Far East. We would hate to see anything that would in any way at all reduce the value of that standard.

“The Far East markets are increasingly more important for us. six per cent to China. It’s a large and growing market for us.”

Announcing the change in its personnel, SalMar did not reference the Chinese investigation. Commenting, Williksen said: “The task of heading SalMar is exciting but is also demanding. Those who know me are aware that I have experienced a strenuous period over the past years, and I now want to focus more on myself for a period of time.”

Lynn Schweisfurth, of the Scottish Salmon Think-Tank, which is critical of the fish farming sector, commented: “The Scottish Government must immediately investigate how salmon from Scotland became implicated in a smuggling ring.”