SINGAPORE - Singapore-born writer Kevin Kwan, whose book inspired the movie Crazy Rich Asians, defaulted on his national service obligations, the Ministry of Defence said on Wednesday in response to queries from The Straits Times.

"Mr Kevin Kwan failed to register for National Service (NS) in 1990, despite notices and letters sent to his overseas address. He also stayed overseas without a valid exit permit. Mr Kwan is therefore wanted for defaulting on his NS obligations," Mindef said.

It added: "In 1994, his application and subsequent appeal to renounce his Singapore citizenship without serving NS were rejected."

Under the Enlistment Act, Mr Kwan is liable for a fine of up to $10,000 and/or imprisonment of up to three years if convicted.

Mr Kwan, who left Singapore at age 11 and now lives in the United States, did not respond to The Straits Times' recent requests for an interview. The 44-year-old was last interviewed by ST last year.

Mr Kwan was a conspicuous absence at the red carpet event for the movie at Capitol Piazza on Tuesday night that featured nearly every Singaporean cast member.

Hundreds gathered for the red carpet premiere on Tuesday to greet the stars of the film Crazy Rich Asians. The main attraction was leading man, Malaysian-British actor Henry Golding, who plays Nick Young, the heir to a fortune amassed by Singapore's wealthiest family.

The film's weekend takings of over US$35 million (S$47.9 million) in the US has far exceeded expectations for the romantic comedy. It was also No. 1 at the US box office over the weekend.

The movie, which was filmed in large part in Singapore and featured nearly 300 crew members who are Singaporean or Singapore permanent residents, had also been hailed as a breakthrough for racial representation in Hollywood and as a good showcase for Singapore.

The movie was supported by the Singapore Tourism Board (STB) and the Singapore Film Commission.

In reply to ST queries on what STB considered in backing the movie, whether Mr Kwan's NS status was relevant and when STB became aware he was a defaulter, STB would only say that it is working with Warner Bros to organise marketing activities around the movie, "so as to promote awareness of destination Singapore and its offerings".

It said it saw the movie as a "natural opening to pique viewers' interest in visiting Singapore".

STB said, without addressing the questions on Mr Kwan: "We expect the exposure from the movie to help bring greater global awareness of our destination and this could potentially attract more visitors over time. Moreover, the movie has profiled Singapore's talents, including the huge cast and crew who were involved in the production."

Mr Kwan migrated at age 11 to Texas in the US with his engineer father, piano-teacher mother and two older brothers.

In Singapore, he grew up in a multi-generational family home in Bukit Timah and attended Anglo-Chinese School (Primary).

His grandfather was Singapore's first Western-trained ophthalmologist, Dr Arthur Kwan, who was for many years the commissioner of the St John Ambulance Brigade and was knighted by Queen Elizabeth II.

Dr Kwan shared a clinic with his brother-in-law, Dr Hu Tsai Kuen, father of Singapore's longest-serving finance minister, Dr Richard Hu.

Should Mr Kwan return to Singapore, he would become the latest defaulter to be dealt with under the new sentencing framework set out by the Courts last year.

In August, while addressing questions about footballer Ben Davis' request for deferment of his NS, Defence Minister Ng Eng Hen said that 13 NS defaulters have been prosecuted under the new framework, and stressed that the Enlistment Act is blind to "personal convenience and considerations".

"In Court, each gave reasons why he did not enlist as required. Some wanted to complete their university degree first before NS... At the core of the Enlistment Act, the critical national need for a strong defence puts aside personal pursuits and mandates that each liable male performs his NS when required," he said.

There have been other high profile NS defaulters in recent years. Last year (2017), two sons of Senior Counsel Tan Chee Meng were jailed for defaulting on their NS obligations.