Ships are facing increasing risks from piracy but the government is "failing" to address the threat, the Commons Transport Committee says.
Piracy involved kidnapping, rape, and murder, said Mrs Dunwoody
MPs have warned the government seems to be "in the dark" about the matter and is "woefully lacking" in its actions to make piracy "a thing of the past".
There were 10 attacks at sea near Iraq last year, they said, with well-armed gangs inflicting serious injuries.
The attacks came despite the number of UK warships in the area, say the MPs.
Speaking of the global threat of violent crime at sea, committee chairman Gwyneth Dunwoody said: "Over the past decade, piracy has increased by 168%.
"[The] government needs to be at the forefront of the fight to destroy piracy. It must demonstrate practical action that international cooperation is succeeding in making piracy a thing of the past.
"That is woefully lacking. So, far from destroying piracy, it is growing. The government does not even know the scale of the problem.
"That is failure by any measure. The government needs to demonstrate a new level of commitment in tackling piracy."
The report said there were "significant" numbers of British, American and other warships in the Iraq area.
"Despite this, the British government seems to have no idea about the source and nature of these attacks. The level of ignorance on the government's part is a matter of gravest concern."
It said there was little incentive for ships' masters to report pirate attacks and that some crews were being overworked and lacked sufficient training which placed them and their vessels at risk from determined pirates.
"In 2005 alone, piracy resulted in over 150 injuries and assaults and over 650 crew members were taken hostage or kidnapped," said Mrs Dunwoody, a Labour MP.
"They were suffered by innocent people travelling lawfully by sea. Even one such attack is one too many."