Immigration officers mentioned pop singers Andy Lau Tak-wah and Aaron Kwok Fu-shing to Man-hon as they tried to find out whether he was from Hong Kong or the mainland.
And in the course of a 65-minute interview they examined his clothes and concluded his rubber shoes were from China.
The investigation report said officers used various approaches to confirm the boy's identity.
When an officer asked Man-hon in Cantonese and Putonghua his name, nickname and address, he got no response. A search was then conducted. 'He noticed that the boy's wrists bore marks of being handcuffed before, apparently. His belly carried some rashes, the lower part of his leg bore some scars and his feet were dirty,' the report said.
A senior officer then took off the boy's clothes and checked his shoes to see whether there was anything that might suggest the boy's identity. They found the boy was not wearing underwear and the trademark label on his T-shirt had been removed.
'His rubber shoes, according to the knowledge of the immigration officer and senior immigration officer, were of a well-known brand in the mainland,' the report said.