A reward of up to £3,000 (€3,509) is being offered for information leading to any arrest and conviction after a monkey was abandoned on a London bus.

The female common marmoset was discovered on a 302 bus waiting in Kensal Rise, north-west London, last Friday.

A mother had been unable to move her buggy down the bus aisle because a laundry bag was sticking out of the luggage bay.

When the bus driver pushed the bag out of the way, the monkey – since named Oyster, after the London travel card – started “chirping and jumping”.

Oyster has been checked by a vet and rehomed at a sanctuary. She was not microchipped.

RSPCA Monkey in boarding London
The RSPCA said the monkey was terrified after being left inside a cage (Photo credit: RSPCA)

Animal charity Peta is offering the reward in a bid to find whoever abandoned her.

Chief Inspector Dew said the force will be looking at CCTV and the logs for scanning on and off the bus to “see if we can locate the person who left her onboard”, adding: “It was clearly intentional.”

Peta Vice-President of Programmes Elisa Allen said the organisation is calling on anyone with information about this case to come forward “so that whoever abandoned Oyster can be held accountable before endangering anyone else”.

“Abandoning an animal is an extraordinary betrayal. This monkey deserved care and protection, not to be discarded like rubbish,” she said.

It is feared to be the “first of many” abandonments after April’s new legislation mandated that all primates kept in England are licensed, the RSPCA said.