A 14-year-old Hong Kong girl arrested for scribbling graffiti on a wall famous for the pro-democracy messages it carried has been sent to a children's home, her lawyer said Tuesday.

Police detained the girl for chalking a flower on the "Lennon Wall", a staircase at the main Admiralty protest site which became plastered with brightly-coloured notes of support for the democracy movement during more than two months of rallies.

Notes and messages have sporadically been posted on the wall since the protest sites were cleared by police earlier in December.

The teenager was arrested in the early hours of December 23 after scrawling on the wall and was detained for 17 hours, said solicitor Patricia Ho.

She was sent to a children's home on Monday for three weeks while a court considers a police application for a care and protection order which could see her removed from her father's care, said Ho.

She described the move as "disproportionate" and "shocking".

The girl has been in trouble with police before, said Ho, but she added there was no evidence that she was not well cared for at home.

In a separate case, a 14-year-old boy could also be removed from his parents following his arrest as police cleared the Mongkok protest camp in late November.

Police have applied for a care and protection order for him.

"These types of orders are usually sought in extreme cases, for example the child is on drugs, or trading drugs or prostituting themselves," Ho told AFP.

"It's a very worrying trend... it's imposing a climate of fear."

The magistrate at Monday's hearing deemed it safer for the teenager to go into a girls' home, Ho said. The application before the court alleges that she is being neglected by her family.

But neither the girl nor her father wanted her to be removed, Ho said.

"She was very upset and said she was afraid of going into the home" in a statement to the court, said Ho.

Her father, who is severely hearing-impaired, also made an emotional statement, pledging to keep an eye on her at all times.

"He said he would want to go wherever she goes," said Ho.

A social worker will investigate the case before the next hearing in January, Ho said.

The next hearing in the teenage boy's case will also take place in January.

Police said they could not comment on the cases as legal proceedings were ongoing, but confirmed that neither teen had been charged since their arrest.

Minors were arrested during the mass protests seeking fully free leadership elections, and at subsequent smaller gatherings.

Police told AFP they did not have a total figure for the number of minors detained. But some as young as 13 were arrested at small Christmas protests in Mongkok, according to police statements.