In a statement to the stock exchange late on Friday, the company said it had engaged legal advisers late last year to investigate share trades by Mr Wong in October.

The report, from law firm Watson Mangioni was provided to the board and its contents remained privileged and confidential, the statement said.

"After due consideration, the board of Sirtex has today terminated Mr Wong's employment, with immediate effect," the company said.

The company said Mr Wong would continue to receive his salary and statutory entitlements up to his date of termination but that all his unvested performance rights would be forfeited.

The company's chief operating officer Nigel Lange will take over as acting chief executive immediately, the company said.

"I look forward to delivering on our strategies, to maximise the potential of our... technology and to reinstate value to our shareholders," he said.

In October Mr Wong pocketed $2.1 million from the sale of shares in his company just one day after he told investors at the Sirtex annual general meeting that it expected "double digit" dose sales in fiscal 2017.

On October 26, Mr Wong sold 74,968 shares in Sirtex. That day, shares in his company traded between $28.07 and $29.30, closing at $28.61. If the entire parcel of shares were sold at the day's low of $28.07 he would have raised $2.1 million from the sale.

The company subsequently abandoned the prediction following pressure from the ASX.

In December the company said it would investigate Mr Wong after shareholder and "other enquiries" as well as media reports over the share trades.

In a statement to the exchange in December, the company said that Mr Wong denied any wrong-doing but also offered to take leave while the investigation was completed.

A week after notifying the sharemarket of the sale, Mr Wong issued a statement saying the shares were offloaded to cover a tax liability after the vesting of rights in the company's shares.