In two cases - at the fourth-floor public podium at IFC mall and at Swire Properties' Park Court outside Pacific Place - security guards allowed filming without condition.

In the third case, staff working for Hong Kong Land in Exchange Square permitted filming of the sculptures on public display, but said tripods were not allowed.

At the fourth location, guards reacted differently as we filmed from a public sidewalk in Quarry Bay. Two guards said we were not permitted to take images of the exterior of Taikoo Place, claiming those images were the property of Swire.

Nevertheless, they took no further action as we continued to shoot, as we insisted filming could take place from a public sidewalk.

The greatest trouble encountered was at the public courtyard at The Center, in Central, which is managed by Citybase Property Management.

Staff said that while the area was public, it was 'under the control' of Citybase and we were required to apply to management for shooting permission.

Security services manager Terence Mok said someone might trip over our tripod, while our Canon XL1 camera - because of its size - would draw too much attention.

'The tripod and the shooting will affect our guests. They will ask, 'What's going on? What's going on? What happened here?'' he said.

After we turned off our cameras, Mr Mok asked us to erase footage of him, saying we had violated his privacy.

We declined to do so, explaining we had identified ourselves as reporters and that the shooting took place in a public area. Mr Mok then called the police, in the apparent belief the police could order the footage to be deleted.

However, the commanding officer who arrived at the scene told Citybase it was not within his authority to order the destruction of the private property of another individual.

The Sunday Morning Post informed Citybase that Mr Mok's image would not be used as part of the video report accompanying this story. The test was to measure the openness of these public spaces, not to highlight the actions of any particular individual.

The police officer proposed to Citybase that it post its rules clearly on how the public may use the courtyard. The Development Bureau on Friday recommended that property owners across Hong Kong do the same.

Spokeswoman Eunice Chan said Citybase had no rules for the courtyard, 'and so there is no issue, as suggested, to post rules in an area where the public can view them'.

She said the security guards had disallowed the use of tripods 'to maintain free flow of passage for the convenience of the public', but did not say why filming was banned.

Asked whether calling the police was an appropriate use of police resources, Ms Chan said this 'should be appreciated as an act to avoid further escalation of arguments'.

However, during 15 minutes of friendly chat as we waited for the police, Mr Mok said we were not being detained, though he wished for us to remain until police arrived to resolve the issue.