There is confusion whether the chair of a powerful Welsh assembly committee has resigned, or is determined to stay.
Lord Elis-Thomas (L) and John Marek have disagreed for months
Assembly presiding officer Dafydd Elis Thomas told BBC Wales his deputy, John Marek, had resigned from the house committee on Thursday afternoon.
Other AMs said they witnessed a furious exchange of views, adding Dr Marek then announced his intention to resign.
But Wrexham AM Dr Marek later denied the reports, which come after months of dispute between the two men.
The house committee was meeting to finalise the assembly's budget for 2007.
Dr Marek has insisted he did not resign. He said it was a private meeting and that he would be breaking assembly rules if he discussed what happened.
However, at least four other committee members have said he did relinquish his post as chairman.
It is not clear if Dr Marek will remain as an ordinary member of the committee, which has a key role in the way the assembly is run.
The incident is the latest in a series of open disagreements between Lord Elis Thomas and Dr Marek, centred on how the assembly should be run after the Government of Wales Bill is implemented.
The pair publicly clashed recently over the treatment of a top official at the assembly.
Dr Marek accused the presiding officer of plotting to remove the assembly clerk Paul Silk without consulting AMs.
Mr Silk, who has been the principal adviser to the presiding officer for almost five years, has decided not to apply for the post of chief executive and assembly clerk.
He will leave his role in January next year, just months before the assembly gets new powers under the Government of Wales Bill.
Plaid Cymru AM Lord Elis-Thomas has said that his deputy, who left Labour to set up independent party Forward Wales, was "pursuing a political interest" over their differences.
The presiding officer admitted he had been unable to come to an agreement on the issue with Dr Marek in private discussions over the past six months.
He also described the row over Mr Silk as the "growing pains of a new democratic institution".