An embattled Clyde River oyster leaseholder fears ruin after the theft of 40,000 baby oysters - the latest in a string of raids that have cost him more thyan $100,000.

The December 23 theft was the latest raid on the leases Ray Wilcox manages with partner Max Ladmore.

The pair entered the industry three years ago and have been robbed of older oysters several times.

Initially, they believed the thefts were opportunistic, with the oysters being sold on Canberra's illicit market.

Now the theft of so many young oysters has Mr Wilcox fearing another farmer, possibly from another river system, is building up stocks at his expense.

"We had three pods stolen with smaller oysters and a fourth pod with larger oysters taken on the night of December 23," Mr Wilcox said.

"It is definitely commercial. They are not oysters people would want to eat, because they are too small.

"We have an oyster farmer, it does not even have to be on this river, who is building up their stocks with Pacific oysters.

"If it is an oyster farmer, he could be selling the bigger ones and also be building up his stock."

Asked if he suspected a Eurobodalla farmer, Mr Wilcox did not rule it out.

"I hate to think it, but it could be," he said.

However, Mr Wilcox said a farmer from another area could also be the culprit.

"They would not have to know the river that well, because they are taking them from a couple of the easiest places," he said.

"They could be coming from somewhere else, but they would have to know oysters."

Mr Wilcox said it would have been very obvious the three pods of young oysters were too small for market.

"They took three pods in a row and when they pulled up one, they would have seen what they were," he said.

"We buy them as babies, when they are the size of a match head," he said.

"We would have got them in August."

Each pod held between 15,000 and 20,000 youngsters, needing another six to eight months to reach sale size.

Mr Wilcox said he was not yet ready to quit, but the latest raid had him contemplating his future.

"I don't care what type of business it is, I can't sustain these kinds of losses for any length of time," he said.

"Other farmers have also been hit lately, but not like this."

Mr Wilcox estimates he has lost $100,000 in combined oysters, equipment and time and said the raids had consequences for the whole industry.

"This is the second-largest industry in the Bay," he said.

"If they did this to everybody, they would finish off the industry here.

"Everybody is starting to put babies into the river and when they get taken, it really hurts.

"We want them to catch [those responsible] and fine them or put them in jail."

In late October, Clyde oyster farmers formed a united front to offer a reward to information leading to a conviction for thefts on the river. Police inquiries are continuing.

To report theft or suspicious activity around an oyster lease phone NSW Police Crime Stoppers 1800 333 000.

• The Bay Post