It promised to have all the key ingredients of a classic soap opera, and the Racing NSW inquiry did not disappoint.

A press pack of some 70 reporters and photographers staked out the horse racing body's head office in Sydney from early Monday morning, swarming over all the main players as they arrived to give evidence.

Trainer Gai Waterhouse slipped in through an underground garage, her immaculate bob unruffled, but her son Tom and husband Robbie were all smiles as they fronted the flashbulbs.

The first to arrive but the last to appear in the inquiry room, Mrs Waterhouse found herself without a seat, but former friend John Singleton gallantly offered her his.

She declined and sat at the opposite end of the table.

There were some 18 people seated around the inquiry table and another 70 or so spectators in the room, settling in for a long day of evidence and insults.

For the cordial relations turned frosty fast.

Singleton was "a sham", "a disgrace" and "a drunk", Mrs Waterhouse alleged, erupting a number of times during the proceedings.

Mr Singleton didn't rise to the bait, instead joking about how much he'd had to drink on the day of the All Aged Stakes on April 27: "I had two to three beers before and as much as I could after," he said, to loud laughter.

But he wasn't the only one drinking that weekend: he said former footballer Andrew Johns had also had a few too many when he said Tom Waterhouse had told him his mother's horse was "off".

"I was agitated, I jumbled my words and now I look like a goose," Mr Johns' written statement to the inquiry read.

The whole affair came down to a game of Chinese whispers, Tom Waterhouse said.

From him to Mr Johns to punter Eddie Hayson and former jockey Allan Robinson - the latter two called a "brothel owner and a beat-up jockey" by Mrs Waterhouse - it's a tangled web of who said what to whom and the inquiry will have quite a job of unravelling the strands.

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