Sunday Times quoted the 26-year-old's friends as saying that he was 'upset' by 'sick' threats earlier, but the striker has now spoke of his bitterness after the incident.

"I have absolutely no idea how they got hold of my number but some of the calls have made me sick to my stomach," Defoe told the Sunday Mirror.

"I cannot accept that it is coming from people with a balanced state of mind."

The England international is poised to leave Fratton Park after one year with Pompey, where he has been the main figure of the team's attack line.

Defoe is reportedly targeted by Manchester City, Juventus as well as former club Tottenham Hotspur.

Family

The Portsmouth hitman also revealed how the threats left his family in dismay.

"It has infuriated and upset my family and left me wondering what on earth possesses people to do things like that," he added.

"I have reported it to officials at the club."

Defoe pulled out of Portsmouth's FA Cup 0-0 draw with Bristol City on Saturday, citing flu.

However, it is believed that the pacey forward is not willing to appear for Tony Adams' side again, in the wake of the threat incident.