The charity faces a rescue bill of £5,000 and is hoping that the enthusiasm people showed for the rescue will translate into donations.
Knight said he was disappointed that individuals and media organisations had made lots of money out of the whale rescue, yet the charity had not received a penny.
In fact, volunteers who rushed to help the mammal have been stung with parking fines of up to £300, which the charity is hoping to have waived.
However, the group is capitalising on the publicity the affair generated by auctioning the watering can used in the rescue.
After hearing that 230 million people had followed the tale of the whale, Faye Archelle, one of the marine medics involved in the 36-hour rescue attempt, decided to auction on eBay the watering can she used to moisten the body of the northern bottlenose whale, which found its way up the Thames to central London last Friday.
Bidding had reached £410 by 5pm on the first day of the 10-day sale.
The auction will also be publicised today at a press conference at the London Zoological Society, when the findings of the post-mortem examination carried out by marine experts are released.