A woman was sexually assaulted in front of her daughter in the parking lot of a business park in Cyberjaya about a week ago - and the police are having a tough time identifying the perpetrator as no surveillance camera was installed there.

According to Sepang district police chief Wan Kamarul Azran Wan Yusof, the incident took place at about 11am on Dec 21 at Tamarind Square.

The victim, aged 31, and her two-year-old daughter were about to enter their car after doing some shopping.

"The victim was at her vehicle, which was parked at Level 2 of the parking lot when an unknown man suddenly came from behind and started to hug and grope her.

"The victim immediately shouted for help but there was no one else in the area. The perpetrator then ran away," Wan Kamarul said in a statement.

He said the victim could not see her attacker's face because he was wearing a face mask. She could only remember that he was wearing long black pants.

"There was no CCTV where the incident occurred. Police have requested the person-in-charge of the CCTV at Tamarind Square to check all their recordings from the time the victim arrived at the park and see if the perpetrator had followed her," Wan Kamarul said.