It’s fair to say that life under lockdown can be boring at times.

Most parents will have come to appreciate the increasingly tricky task of keeping the kids entertained.

But as the weather warms up, plenty of children will be looking to the garden for new ways to pass the time.

And for two French brothers, that resulted in a valuable discovery.

Their parents decided to leave Paris when France imposed a lockdown and move to a family home in the town of Vendôme, south-west of the capital.

The boys, both aged about 10, asked to build a makeshift hut in the garden using branches, leaves and sheets.

Their father, a businessman in his 60s, told them that they could use their late grandmother’s sheets, which were in a spare room.

When they went to collect them “two fairly heavy objects” fell out, Philippe Rouillac, a local auctioneer, he said. “They didn’t pay attention to them and put them back.”

But the boys soon told their father about the discovery.

“He asked them to go and get them,” Mr Rouillac said. “But he initially believed they were knife holders that belonged to the grandmother.”

He contacted Mr Rouillac’s company to double check and, after sending a few photographs, he was told the good news.

The objects were not knife holders, but two gold bars weighing 1kg (2.2lb) each.

Both bars are now listed on the auctioneer’s website with an estimated value of 40,000 euros (£35,800; $43,800) a piece.

It turned out that the bars were purchased by the grandmother in 1967 and even come with a proof of purchase.