For people living near the River Hiz in Hitchin, the site of a moorhen guarding her chicks on a partially submerged shopping trolley had created a popular viewing gallery for all to see.

So when the trolley disappeared on Friday, it provoked anger among locals.

The trolley was removed by North Herts District Council contractors, who claim the moorhens had gone by the time they retrieved it.

Councillor Peter Burt, who is responsible for environment affairs at the council, said: “Before the shopping trolley was cleared from the river near Sainsbury’s, our contractors inspected the nest and found it to be empty. One of the eggs had hatched and the chick was seen with the mother nearby.

“Another egg was floating nearby suggesting it had failed to thrive and had died.”

But people living nearby dispute the claim that the nest was empty, and members of the police rural operations support team are investigating.

A police spokesman said: “A member of the public reported that a moorhen had been nesting in a shopping trolley that was in the river.

“Four of its young had hatched and two eggs were still in the nest when at some point between 9.30am and 1pm on Friday the nest was destroyed.”

Andrew Smart, who lives near the river, said: “At 7pm when passing I was shocked to see that the trolley had been removed and the nest destroyed. It nested last year on a Christmas tree.”

Another local, Angela Johnson, said: “At 9.30am that nest was being guarded by the mother. At 1.30pm it was all gone. There was nothing abandoned about that nest.”

Anyone with information should contact Det Con Amanda Matthews on 101, quoting crime reference G1/15/1667.