The first minister denied accusations from opposition parties that the health minister had interfered with an independent report on NHS reconfiguration plans.
Carwyn Jones AM was answering member's questions in the Siambr, on 10 July 2012.
BBC Wales has revealed that an independent academic report outlining NHS reforms may have been influenced by contacts between the author and senior government officials.
In a series of emails, report author Professor Marcus Longley asks civil servants for "killer facts" to support the case for changes.
However Professor Marcus Longley and the government insist the report was independent.
Plaid Cymru Leader Leanne Wood called on the first minister to make a statement on whether or not Health Minister Lesley Griffiths was "involved" in these emails.
The leader of the Liberal Democrats Kirsty Williams and the Conservatives Andrew RT Davies also challenged Carwyn Jones on the emails.
However the first minister denied that the health minister had any knowledge of these emails and said that "this is the most tenuous political story I've ever come across".
He said the Conservative health spokesperson Darren Millar was wrong to attack the independent academic professor, Marcus Longley, in a BBC Wales radio interview.
The first minister advised Mr Millar to "seek legal advice" after questioning the independence of a leading health economist.
Mr Davies responded to Mr Jones' comments and accused the first minster of "deflecting" the subject and added that Welsh Labour was trying to "bully itself out of a hole".
Mr Jones also answered questions on animal health, the Welsh government's Autism policy and supporting pathological gamblers.
Read this in Welsh.