A rare painting by celebrated marine artist Charles Napier Hemy has been snapped up at auction at a fraction of its value by Falmouth Art Gallery thanks to two mystery benefactors who made a “substantial” donation towards its purchase.

Just ten days before Hemy’s Hauling in the Nets was due to go under the hammer at Bonhams in Knightsbridge, a lady walked into the gallery and suggested to director Henrietta Boex that it should be bought and brought back to Falmouth.

“They (the benefactors) had received the auction catalogue and felt strongly that this piece should come back to Falmouth,” said Henrietta. “They felt it was an important piece for Falmouth.”

So keen was lady to see that happen, that she offered a generous sum of money, on her and her fellow benefactor’s behalf. The race was then on to secure further funding with applications going to the Art Fund and Arts Council/V&A Purchase Grant Fund, both of which were successful.

“We were just in time as the Art Fund and the V&A have to have applications seven days before an auction and it was reassuring that both of them said ‘yes, absolutely we will support you,’” said Henrietta.

“We did not have the final grant in place until 3.30pm (last Tuesday) so I had to rush up to London for the sale the next day. It was all very exciting, but I didn’t really expect to be bringing it home.”

The painting carried an estimate of between £25,000 and £35,000 and although there were telephone bidders, the price stalled at £35,000. “It all went silent so I waited and still nothing happened which is when I raised my paddle and the price went up to £38,000, and I won,” said Henrietta. “I had expected it to go for more.”

The painting, which shows two oyster fishermen at work in Falmouth harbour and was created in around 1886, had been valued by Antiques Roadshow expert Rupert Maas on behalf of the art gallery at £80,000.

The painting has now been delivered to the town council owned art gallery and will be professionally cleaned and possibly reframed before it goes on show as part of the Tall Ships exhibition in July.

Henrietta also hopes it will be “the poster girl” for this year’s oyster festival in October.

“The painting is a valuable asset for the town and is just the sort of piece that will bring people into the gallery,” she said.