Tuesday's afternoon session at the RHI Inquiry heard evidence from former DUP special adviser Timothy Cairns about a explosive breakfast meeting with Jonathan Bell at a London hotel in summer 2015.
Mr Cairns worked under the then minister for the Department of Trade, Enterprise and Investment (DETI) Jonathan Bell when concerns were raised about the RHI scheme in 2015.
Mr Cairns has made a series of explosive allegations against Mr Bell, including that he tried to break his finger and that he was so drunk during a trip to America that he fell asleep on a bar in New York.
In the morning session on Tuesday he detailed the inner workings of how the DUP operated.
In the afternoon session he alleged that Mr Bell would not read submissions given to him, saying he lacked focus and would rely on his special advisers for summaries.
He said one strategy for briefing Mr Bell was to "physically put [the documents] in front of him", but said it was not always successful.
"You can lead a horse to water, but you can't make him drink," he said.
- Follow Tuesday morning's coverage here.
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Read live updates from Tuesday's evidence here: