Police said on Tuesday they had arrested one of their own officers and a woman, 47, on suspicion of conspiracy to defraud.
It's understood that the officer concerned is Harbour Chan, an assistant commander in Sha Tin District, who is also known for being an active blogger on social media.
The pair are suspected of providing forged documents to two banks when applying for a mortgage and have been detained for investigation, a force spokesman said.
He added that the 50-year-old officer would be suspended from duties, though an initial investigation suggested the alleged offence was not linked to his work.
The police said they attach great importance to officers' conduct and will not tolerate any illegal acts.