Security minister Chris Tang on Sunday did not say whether Hong Kong police intend to arrest a Danish artist whose sculpture was seized by authorities earlier in the year as evidence relating to a national security case.

Local newspaper Sing Tao Daily earlier quoted sources as saying that national security officers have formulated an operation to arrest Jens Galschiot, the sculptor of "Pillar of Shame", and looked into having the Office for Safeguarding National Security exercise jurisdiction and the case tried on the mainland.

In a letter to SAR authorities later, the Danish sculptor said he was "perplexed" and asked for clarifications on the charges and whether an arrest warrant has been issued.

Galschiot said the secretary for security replied by saying police would not respond to any enquiry in relation to individual cases, but said it's common for those seeking to endanger national security to engage in acts under the pretexts of "peaceful advocacy" and "artistic creations".

Speaking to the media on Sunday before embarking on a foreign trip, Tang said any police arrests will be based on facts, evidence and relevant laws.

"If people wrote me a letter, including thieves, asking whether they are wanted, whether they would be arrested upon arrival, I would not answer, because I would not tell a thief that I'm going to arrest them."

Tang said in some cases, such as for the eight people wanted for national security offences, publicly disclosing their arrest warrants served to tell others not to contact or help them.