The 17-month-old boy is thought to have got stuck after kneeling up in the child seat.

Ian Walker, Haywards Heath watch manager, said: "His leg went shooting back behind him and got stuck between the back rest of the seat and the plastic base.

"He was a little bit distressed when we arrived."

Haywards Heath fire and rescue officers used tools to prise off the plastic seat giving them the space to free him.

The trolley was left undamaged during the incident on Monday, March 2, at 3.46pm in the Haywards Heath branch of Sainsbury's.

Mr Walker added: "His mother was there looking after him and he was fine."

Praising the boy's mum for her prompt action in calling them, he urged anyone who was in danger or at risk to dial 999 without delay.