Mbongwa Dlamini, President of the Swaziland National Association of Teachers (SNAT), was detained by the police for standing in front of a picture of the absolute monarch King Mswati III while wearing a cap.
He was at the Sandlane Boarder Post and Swazi police denied him entry back into the Swaziland (eSwatini) from South Africa.
Dlamini told the Swaziland News, an online newspaper, that he was told he had to remove the cap he was wearing before his passport would be stamped.
The News reported it is an offence under customary law to wear a hat in front of King Mswati's picture and people are expected to remove their hats to show respect.
The News reported Dlamini saying, 'When I asked why should I remove it, they showed me the picture of the King on the wall saying that was the reason I should remove my cap.' He added police harassed and detained him. The incident happened on Boxing Day. He was later released.
Sikelela Dlamini, SNAT Secretary General said Mbongwa Dlamini was being victimized and deprived his right to freedom of movement.
A police spokesperson later said Mbongwa Dlamini had only been asked to remove his hat for identification purposes.
In 2012 a 17-year-old schoolboy was fined E400 by Swazi National Court for ripping up a photograph of King Mswati.
The Swazi Observer, a newspaper in effect owned by the King, reported at the time court president Makhuluma Ndwandwe warned him that it was a serious offence and ordered that he be sent to jail where he could be corrected. He was given a fine instead.