Inkhosikati LaDube was ordered to "immediately leave the palace" by royal governor Timothy Mthethwa, who was accompanied by other senior members of the royal family.

LaDube, 23, told the Sunday Times yesterday she had had an argument with a security guard who refused to let her out of the palace last Saturday.

She wanted to take the youngest of her three children, aged 2, to hospital after she had injured herself while playing - but the guard said she was not allowed to leave.

"[He] threatened to hit me, saying I am not going anywhere with my child, who was bleeding from a deep wound," she said.

LaDube said an altercation ensued and she was "physically prevented" from leaving the palace. "I had to protect myself so I [pepper]-sprayed him in the eyes."

The matter was reported to the Queen Mother, who apparently decided that LaDube had been disrespectful and had to be kicked out.

"I couldn't even take all my stuff, because they just said 'you have to pack and leave now'," she said. Her children remain at the palace.

An emotional LaDube - who said she had not seen her husband for almost a year - said she was punched and kicked by another security guard at the palace in July when she wanted to see the king.

City Press last year reported that LaDube - who married the king when she was 16 - was caught in bed with the king's friend and financial advisor at a luxury hotel in Swaziland - an allegation she denied.

Swaziland Solidarity Network, a South-Africa based umbrella organisation of Swazi pro-democracy NGOs, has in a statement lambasted the king for LaDube's "brutal eviction".

Spokesman Lucky Lukhele said they had established that the eviction was ordered by the king because of earlier infidelity accusations against her. "The ill-treatment that LaDube has endured and the subsequent separation from her children is a very inhumane act."

Lukhele said "traditionally" such things shouldn't happen when the sacred Incwala ritual (the first fruits ceremony) was under way.

"Mswati was hoping to use his seclusion [a period during which he doesn't appear in public] as an alibi to pretend he had nothing to do with this eviction."

He said they have established from "royal insiders" that the king told the Queen Mother he did not want to find LaDube at the palace "when he emerges from seclusion".

LaDube is the third queen to leave the royal household since 2004.

Repeated attempts to reach Mthethwa were unsuccessful.