Angry Adidas customers, some who queued for more than 36 hours, posted a flood of complaints on social media about the way the brand handled the release of limited-edition shoes yesterday in Orchard Road.

Hundreds of customers were crowded around the store at about 10am when the official queue for the shoes, a limited-edition collaboration with Bathing Ape, was supposed to start.

"Only available at Adidas Originals Pacific Plaza. Customers are entitled to purchase only one pair of Adidas Originals x Bape NMD R1 on a first come, first served basis," Adidas announced on its Facebook page on Friday.

It is understood that at least a hundred people queued overnight, and some had been waiting outside the store for two nights since Thursday for the shoes, which cost $229.

Mr Ong, who did not want to give his full name, told The Sunday Times that he and two of his friends began queuing at about 9pm on Thursday.

Mr Mohd Hafiz, 36, and his friends had also been queueing from Thursday night, but for another limited-edition shoe that was released on Friday. They later joined the Bathing Ape shoe queue.

Mr Hafiz's friend even booked a room at the Royal Plaza hotel beside the store so that they could take turns to shower and rest while queueing.

However, questions to the staff about the number of shoes available and about where the queue should start went unanswered.

At close to 10am yesterday, staff from the Adidas store moved customers who were waiting outside to the lane beside the store, and set up barriers for an "official" queue.

"Everything was messed up," Mr Ong, 26, said. "People who were first became last."

A few people told The Sunday Times that one staff member was particularly rude.

Some people left while others began pushing to get to the front of the waiting crowd.

About 10 disgruntled customers said they felt it was unfair, as it was not clear how the staff picked some people to join the official queue, which they said had about 50 to 100 people.

People were picked "randomly", said Mr Douglas Ng, 25, who started queueing at about 5pm on Friday.

Mr Ng, the owner of Fishball Story, said he was near the front of the crowd, but by then, he was more concerned about the safety of his girlfriend and himself.

People seemed angry, and ventilation was not good, he said.

"People were pushing and shoving as they were frustrated. I admit it was difficult to handle, but the staff did not seem prepared for this at all," he said. "This will definitely be the first and last time for me."

Mr Ong said he and his friends took leave from work to queue, and each had only about three hours of sleep during the wait, but they left empty-handed.

The shoes are seen as a collector's item and videos and photos of long queues for them in cities around the world can be seen on social media.

When The Sunday Times approached the store yesterday, staff said they were unable to comment.

A statement from Adidas on Sunday said that they were aware of the matter and are investigating the incident.

"Our customers and the public's safety are of utmost priority. We regret that some fans were unable to purchase the limited edition BAPE NMD R1 or Firebird Track Jacket. We take all of the feedback from those affected and will take all necessary steps to improve the experience for future limited edition launches. We thank you for your continued support," the statement said.

This article was updated with a statement from Adidas on Nov 27, 2016