A lorry driver has been detained by the police for alleged incest involving his teenage step-daughter.

The 19-year-old has since given birth to a baby girl.

The police have remanded the suspect for six days to facilitate investigations.

Ipoh police chief, ACP Sum Chang Keong said the arrest followed a report lodged by the suspect's wife on May 29, at the Kampung Simee police station here.

He said the 40-year-old wife felt betrayed by the lorry driver when she learnt of his secret affair with her daughter.

"The woman has been married to the suspect since 2011, and has a four-year-old daughter from their marriage," Sum said in a statement here yesterday.

The woman only discovered her husband's infidelity after finding a letter from the hospital stating that her daughter was discharged from Hospital Raja Permaisuri Bainun after giving birth to a baby girl.