A 42-year-old food stall assistant went on trial in the High Court yesterday for allegedly sexually abusing his biological daughter over a period of more than two years when she was between 11 and 13 years old.

The man pleaded not guilty to 10 charges - four for sexual assault by penetration, five for molestation, and one for committing an indecent act with a child - allegedly committed between the end of 2011 and April 2014.

The parties cannot be named to protect the identity of the victim, who is now 15 years old.

The prosecution's case is that the man first sexually abused the girl - the elder of his two daughters - around the end of 2011 in her younger brother's room.

The accused allegedly asked her to massage his leg and then grabbed her hand to commit an indecent act.

Subsequently, most of the abuse took place in the master bedroom of the family's flat, the court was told.

"The accused would ensure that the door was closed and locked before performing the acts of sexual abuse on the victim," Deputy Public Prosecutor April Phang said in her opening address.

After the last alleged incident on April 15, 2014, the girl told her mother about the abuse through the WhatsApp messaging app.

Nearly 20 family members and friends of the accused attended the hearing but the courtroom was later cleared as the prosecution applied for the girl to testify behind closed doors.

The trial continues today.

The most serious offence faced by the accused, sexual assault by penetration of a person under the age 14, carries between eight and 20 years' jail and at least 12 strokes of the cane.