The 23-year-old motorcyclist who died in an accident on Seletar Expressway (SLE) on Sunday has been identified as Mr Faiz Salim.

The Straits Times understands that the motorcycle skidded and hit a lorry on the SLE, heading towards the Bukit Timah Expressway, at about 1.30pm.

Mr Faiz recently completed his national service with the police force.

His friend, who gave his name only as Mr Salam, said Mr Faiz, the eldest of five children, was buried at about 4pm on Monday, after funeral rites and prayers were done at his Woodlands home.

"He was a very close buddy of mine," said Mr Salam. "I first met him when I was doing national service in May last year. We were in the same team. He was a very good guy, very fun to be with, someone you could depend on. He would bring his laughter with him everywhere he went."

Mr Salam, 23, said he first found out that Mr Faiz was in trouble from a friend on social media, who asked him if Mr Faiz was in hospital.

"I was shocked, and asked why he was in hospital. I texted and called Faiz but he didn't reply," he said.

"I thought it was just a normal accident, until his sister told me he had already left us. My heart sank. I could not believe what I heard," said Mr Salam, who recently became an operationally ready national serviceman.

He last met Mr Faiz on Saturday, and they went to the gym together.

On social media, friends paid tribute to Mr Faiz, and one of them, Mr Eddy Wahid, posted a photo of Mr Faiz on Sunday. "Those who know my dearest brother Faiz... He met with an accident this afternoon and he just passed away," he wrote.

Mr Luqman Nurhakeem, in a comment on Facebook, said Mr Faiz was "a good and thoughtful friend".

"May Allah grant him peace in the heavens and may He ease the grief of his family and friends," he wrote.

Facebook user Kiki CuteCute said he was shocked by the news because he and Mr Faiz were just sending SMS messages to each other a day earlier. He wrote: "Still remember the day we made friends... I'm going to miss you so much, bro... Your book has ended but our prayers will always be with you. Al-fateha to you buddy. You will be missed. It's time for you to rest."

The 48-year-old lorry driver involved in the accident is assisting in investigations.