An email was sent by billionaire Marl Cuban to his broker asking if the propriety of a sale of shares which is now the basis of a case filed by the US Securities and Exchange Commission accusing him of insider information.

The email read, "I wanted to make sure I was 100% kosher on that trade. Can you check with your folks to make sure all is cool." The email was sent to Charles McKinney, who was then the senior vice president of UBS Financial Services Inc. It was sent the day after the transaction was made.

The message was presented as evidence to jurors at a Dallas federal court as this was the first full day of defense the owner of the NBA's Dallas Mavericks for his trial on insider trading charges. The SEC had alleged Cuban sold USD7.9 million worth of stock in Canadian internet company Mamma.com in 2004 to avoid a possible USD750,000 loss after he learned about nonpublic information that would dilute his shares. At the time, the company was in the process of divesting shares through a private placement plan, to which the SEC discovered in 2008 and now the subject of this case.

Cuban earlier testified that he did nothing wrong. The SEC is seeking penalties and fines he earned because of the deal as well as other monetary charges.