Organisers of the Janji Demokrasi rally said today they were not aware that a rally participant had directed his bare buttocks at pictures of Prime Minister Najib Abdul Razak and his wife Rosmah Mansor.
Gabungan Janji working committee member Maria Chin Abdullah said the incident appeared to have taken place on the opposite side of where the organisers were at Dataran Merdeka last night.
"We don't support this sort of action. It's not the way to behave. We don't support it at all," Maria said when contacted.
"We did not encourage this sort of behaviour and have even told the people not to bring placards".
In a picture of the incident now circulating on the Internet, a man who appears to be in his 20s, is seen with his pants lowered and exposing his buttocks at pictures of Najib, Rosmah as well as Election Commission chairperson Abdul Aziz Yusof.
The public figures' pictures were lined up on the ground, near yellow daisies and a bandana with the words 'Janji Bersih', and were surrounded by people taking pictures of the ensemble.
Another man is seen applauding the mooning while another person shows his middle finger at the pictures of the public figures.
In a video uploaded onto YouTube by pro-BN blogger Yuseri Yusoff, a large crowd steps on the now-ripped pictures of Najib and Rosmah, supposedly after the mooning incident.
Another pro-BN blog, Gossip Rakyat (GR), claims that the youth who dropped his pants has been identified.
"GR understands that one of the youths is paid by Pakatan (Rakyat) to do this despicable act of dropping his pants in public and trying to defecate on the PM's picture.
"GR will publish (his identity) in the next article. Just wait. You can't run anywhere. We hope the authorities will investigate this," the blog says.
About 10,000 people attended the rally that began at 11 last night, despite it being declared illegal by the police in a letter to organisers received at 2.15pm the same day.
Despite the peaceful outcome of the rally, police are investigating the organisers under the Peaceful Assembly Act 2012.
The rally was aimed at reminding the government of its unfulfilled promises for clean and fair elections.
Its name plays on the government's official theme for the national day celebrations, Janji Ditepati (Promises Fulfilled), which is also the BN’s election campaign slogan.