The Scottish champions were well beaten on the day, two goals from Connor Goldson securing a 2-0 victory for their arch-rivals and opening up the gap at the top of the table to four points.
Celtic’s team for the clash was published online prematurely and Lennon says they will do everything they can to get to the bottom of it.
Neil Lennon was disgusted to find out that someone had leaked Celtic’s starting XI
‘I don’t know, it’s not great. Somebody within the club is doing us in, basically, and that’s disgusting, I think,’ he told BBC Sport after the defeat.
‘We’ll try [to get to the bottom of it], we’ll work at it. It’s very disappointing.
‘Of course it does [make my job more difficult]. I keep talking about a sense of privacy around our club but that doesn’t seem to be the case for some people. That’s very disappointing from my point of view.
‘We’ve got a run of games now where hopefully players will get fitter, sharper and we get players back from illness as well, then things will start looking better, but this [match] was always going to be an uphill task.’
The reigning Scottish champions suffered a 2-0 defeat at home to their city rivals
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