im a sri lankan passport holder

im travelling to japan and have transit in hong kong. I understand I need to apply for transit visa. I was deported from hong kong 2012, because I didnt have entry pemit to enter the country. they didnt let me enter the country and they returned me on the same day. I dont have any stamp on my passport that indicate any deportation. do I have to inform that incidence when I apply for transit entry permit?