A retired Indonesian general was questioned by officers at Singapore's Changi Airport last week as part of "screening procedures", the Republic's Immigration and Checkpoints Authority (ICA) said yesterday.

The agency was responding to local media reports as well as online posts by former three-star general Suryo Prabowo which claimed that he was denied entry to Singapore because he was "blacklisted".

Mr Suryo, who retired as chief of general staff of the Indonesian armed forces (TNI) in 2012, was in transit at Changi Airport on Wednesday morning.

In a series of Facebook posts, he complained that the ICA officers who stopped him subjected him to a lengthy interview. He also claimed he was "blacklisted for reasons that are not clear" and has demanded that the Singapore authorities apologise for how he was treated. The 62-year-old added that if Singapore was "not friendly towards the people of Indonesia, perhaps the Indonesian government needs to review the policy of cooperation in counter-terrorism as well as other bilateral cooperation with Singapore".

In a response posted on its website, the ICA said Mr Suryo was interviewed by its officers for about 30 minutes from 5.35am, and then allowed to continue on his journey. "He was informed by ICA officers that the interview was part of the screening procedures for border security," the ICA said.

"As part of the immigration clearance process, travellers to Singapore may be subjected to additional interview and/or screening. These procedures are conducted at all of Singapore's checkpoints."

Indonesia's Antara news reported on Friday that TNI chief Gatot Nurmantyo had since lodged a protest note with the Singapore defence attache in Jakarta over the incident. "I'm not pleased with how the Singapore Government has treated a former TNI soldier... We have also written to the Foreign Ministry to lodge a note of protest with Singapore," he said.

Indonesian Foreign Minister Retno Marsudi told Tempo news that Mr Suryo was not blacklisted or banned from entering Singapore, adding that he was "only delayed" at the airport.

The incident comes days before Wednesday's Indonesia-Singapore leaders' retreat in Semarang, where President Joko Widodo and Prime Minister Lee Hsien Loong will meet to discuss economic collaborations between the two countries, among other matters.