The Aviva Premiership club maintain they cannot be held responsible for the criminal activity of former team manager Mike Scott, who gave false information to both the club and the RFU over Keats' visa, and their appeal over a five-point deduction and £15,000 fine will be heard on Thursday.
Copsey told Press Association Sport: "We feel we have a very good case. They are holding London Welsh responsible for the actions of an individual that worked for the club who went out of his way to deceive both the RFU and the club."
Scott made a mistake when he applied for an ancestry visa for the New Zealand-born scrum-half but instead of resubmitting it he attempted to cover it up.
Scott told the club that a visa had been granted and he submitted false documents to the RFU, including a forged passport, in a bid to pass Keats off as having been born in England.
The original verdict described Scott, who has accepted a police caution, as a "rogue employee" but it also criticised both London Welsh and the RFU for not being more vigilant.
"The verdict was harsh and disappointing, especially given some of the evidence about how this whole process happened, added Copsey. "I think we should be judged by the RFU standards as much as London Welsh standards. We were both given false information. As a club we unearthed that false information.
"The RFU were aware of the facts as much as were - a different set of facts - and had their suspicions and did not act upon it.
"If we are going to be held up, we should be held up by their standards. They have a duty for the protection of this process as well."
Asked whether the RFU should therefore also be fined, if the London Welsh appeal fails, Copsey said: Yes. The bottom line, yes."
- Sports & Recreation
- London Welsh