NZ models' claims of drugging and groping overshadow Justin Bieber's visit

Bailey Scarlett claims she had her drink spiked at a party hosted by Justin Bieber. Photos/ Channel 9 / Getty Images

A young Kiwi model claims she backhanded Justin Bieber after he grabbed her breast and another New Zealand model claims to have been drugged at a party thrown by the pop star.

Sarah Harris said Bieber grabbed her breast at a Playboy Mansion party in Los Angeles, while 18-year-old Bailey Scarlett believes her drink was spiked at a party attended by Bieber in Melbourne.

Speaking to Australian radio station The Edge this week, Ms Harris said Bieber was leaving last month's do when he grabbed her breast.

"It was my instant reaction to just backhand him across the face," she said.

Bieber was at the party with reality television personality Kylie Jenner, Ms Harris said.

"He kind of freaked out and didn't even say anything and then Kylie Jenner pulled the finger at me and then security took them both out."

Sarah Harris says she slapped Bieber after he allegedly groped her. Photo / Instagram

She said Bieber returned to the house three days later to apologise, and the pair now got along okay.

Ms Scarlett wrote a since-deleted Facebook post that she thought her drink was spiked at a party in a Melbourne studio, which 21-year-old Bieber attended. A source close to Bieber has told media there was no suggestion the star was involved in the alleged incident.

Ms Scarlett wrote how she drank a vodka lemonade and had a shot with Bieber before becoming ill. She began "drifting in and out of consciousness". She was due to appear on Australian television show A Current Affair last night to talk about the alleged incident. Bieber's camp has been approached for comment.

The owner of the Melbourne studio which hosted the party on Sunday night, Jimi Wyatt, told AAP the studio's CCTV footage shows nobody tampered with the woman's drink.

Victoria Police confirmed they had attended the incident on Sunday where a woman told police she believed her drink had been spiked. The woman had not yet made an official report to police.

"The woman was conveyed to hospital for medical treatment and has been advised to attend the Richmond police station to make an official report," a police spokeswoman said.

Bieber is on a promotional trip of Australia and New Zealand and is due to visit New Zealand for an intimate concert tomorrow.