A video clip showing an assembly member making a rude gesture has been posted on the video sharing website YouTube.
Mick Bates was smiling just after making the gesture
The clip taken from Tuesday's assembly session clearly shows Liberal Democrat AM Mick Bates raising his middle finger to the laughter of other AMs.
He appeared to be responding to a reprimand from the presiding officer, Dafydd Elis-Thomas.
But Mr Bates has told BBC Wales it was not aimed at anyone and certainly not at Lord Elis-Thomas.
Mr Bates explained that it was part of a joke with fellow AMs about different ways of pressing their voting buttons, although he did intend to make that particular gesture.
He said: "My gesture was not directed at the presiding officer, for whom I have enormous respect and affection.
Fellow AM Eleanor Burnham put out her hand to tick off Mr Bates
"I was showing Rhodri Glyn Thomas which finger he should use to operate the assembly's modern push button voting system."
Mr Bates, who represents Montgomeryshire, added: "If anyone has taken offence, then of course I apologise for that."
It is not clear who posted the film on the website, or whether the pictures are from the official recording of assembly procedures.
Mr Bates previously raised eyebrows in the assembly chamber when he appeared for a debate dressed as Father Christmas to raise funds for charity.
Lord Elis-Thomas has yet to comment on the incident.