After lying abandoned in a condominium basement carpark for over half a year, a string of supermarket trolleys was removed yesterday, after a social media post went viral.

A Facebook user, who wanted to be known only as Mr Tan, uploaded a photo of over 20 supermarket trolleys from various chains, parked in the carpark of Silversea condominium in Marine Parade.

The trolleys, which were placed in the parking space reserved for disabled passengers, "obstructed" the way, said Mr Tan in his post which has been shared over 175 times since it was put up on Sunday.

When The Straits Times visited the condominium yesterday afternoon, workers were seen clearing the trolleys.

Mr Tan said he was surprised they had been left there for so long.

The trolleys likely came from supermarkets at Parkway Parade, about a five-minute walk away.

A maid who declined to be named said the Silversea security guards are used to residents pushing supermarket trolleys to the condominium. "If you are a resident, there is no problem," she said.

The condominium's management declined to comment.

Supermarkets islandwide have long grappled with the problem of missing carts. Dairy Farm Group, which runs Giant and Cold Storage, said that between them, the two supermarkets lose an average of 1,000 trolleys a year.

NTUC FairPrice too has lost about 1,000 trolleys each year, spending an estimated $150,000 on repairing, replacing and retrieving abandoned trolleys. Its staff start work at 7am and end as late as 11pm, retrieving trolleys. Some have had to be wheeled back from over 2.5km away.

Mr Seah Kian Peng, chief executive officer of FairPrice, said: "Not returning the trolleys is an inconvenience to retailers and shoppers."

The three supermarket chains receive reports on abandoned trolleys through hotlines and social media. The Municipal Services Office (MSO) OneService App also lets those who spot an abandoned trolley report it to the respective supermarkets. Out of 150 FairPrice trolleys reported found each month, 100 are through the mobile app.

Giant and Cold Storage have also put up signs to remind shoppers that trolleys are not permitted beyond the store or carparks.

But despite these efforts, the problem remains. MSO urged the public to be responsible and return the trolleys after use.

Mr Seah stressed: "It is a societal norm and basic courtesy to take something and return it."