Celebrity cosmetic surgeon Vicki Belo on Thursday apologized to the Senate for her failure to attend the upper chamber's joint committee hearing on the sex video scandal involving her ex-boyfriend, Dr. Hayden Kho.

In an affidavit submitted by her legal counsel Adel Tamano, Belo said she is in Europe with her two children, Cristall and Quark, to tape episodes of her new show "Belo 101." She said the trip had been planned in advance and that she would return on June 9.

Belo denied having a hand in the distribution of the sex videos made by Kho.

Tamano said his client is willing to cooperate in the Senate investigation but requested that she be questioned under executive session

Sen. Ramon "Bong" Revilla Jr. earlier called for a Senate investigation on Kho after accusing the celebrity doctor of making at least 40 videos of his sexual trysts with various women including actress Katrina Halili. Several of the videos have spread virally on the Internet through various file-sharing sites.

Kho has publicly apologized for making the videos but said he was not responsible for putting the videos online.

Senator Jamby Madrigal earlier turned down Kho's request for a closed-door hearing on the Senate probe on his sex videos.

The senator, meanwhile, clarified that she will conduct a "partial" executive session to prevent the public from hearing the more prurient details of the sex scandal.

Madrigal also assured the public and some senators, who have suggested to postpone the hearing, that the Hayden-Halili sex video will not be played during the hearing, even on executive session.

The National Bureau of Investigation and the Philippine Drug Enforcement Agency said they will conduct separate investigations on the various personalities involved in the scandal for possible violations of existing laws against pornography and illegal drugs. Kho's mother, Irene, earlier said it was Halili who taught Kho how to use drugs.

The Philippine Medical Association is also conducting an investigation on whether Kho should be stripped of his license for violating ethical standards.