Thomson had provided Melbourne gangland figure Tony Mokbel with a personal reference, saying he "understood" Mokbel had been married for the past eight years and also understood that Mokbel had been "a responsible, caring husband and father". It was later revealed by the media that up until 2000, there had been only one mention of Tony Mokbel in the media, a positive article in the "Herald Sun" about the contributions Mokbel's businesses made to the local economy in Moreland, in and near Thomson's electorate of Wills; and that the National Australia Bank had regarded Mokbel as a legitimate property developer worth some $15 million, in whom they invested until his arrest in August 2001. Thomson resigned from Labor's front bench after the reference became public. He also released the text of the letter, commenting that he did not know Mokbel and that "the reference, as you will be able to see, was more of a pro-forma character (reference)."