Tourism and Leisure Minister Martyn Quayle has had to apologise over answers given to the Legislative Council on the concert by the London Metropolitan Orchestra, at the Villa Marina during TT week.
Political member of the DTL Juan Turner last week said 815 people went to the event, staged to celebrate the inaugural TTXGP, when in fact the figure was 551.
In a letter apologising for the mistake, Mr Quayle also admitted that as worries grew over flagging ticket sales, government workers were offered a last-minute special offer to go.
He said this had been advertised by the DTL on the Government intranet, rather than by email.

Researching your Manx family history can be a very interesting and rewarding hobby. Trace your roots in the Isle of Man with our helpful of guide.