Gerry and Kate McCann speak with journalists at the court in Lisbon June 16, 2014. Gerry and Kate McCann, the parents of missing British girl Madeleine McCann, appeared at a Lisbon court after they launched libel action against a Portuguese former police chief, who said in a book that Madeleine's parents covered up the death of their daughter. Reuters/Rafael Marchante

The family of Madeleine McCann, a 3-year-old British girl who went missing seven years ago, has been subject to a series of vile online messages, including death threats, a report said Thursday, adding that the London's Metropolitan Police, which is in talks with the UK prosecuting authorities, is investigating the matter.

According to authorities, Madeleine's parents Kate and Gerry McCann have received more than 80 pages of Tweets, Facebook posts and messages on online forums. The family has been the target of hundreds of offensive messages over the past few years by some Internet users, who believe that the McCanns were involved in the disappearance of their daughter in Portugal in 2007, Sky News reported.

Some messages said that the McCanns should be tortured and killed, while some were even aimed at Madeleine's younger siblings. In addition, morphed images showing the McCanns have also been circulated online. Campaigners have urged police and UK lawmakers to control this kind of online.

“In consultation with the Crown Prosecution Service and the McCann family the material will now be assessed and decisions made as to what further action if any should be undertaken,” Police wrote to campaigners.

The 3-year-old vanished when her parents left their villa to dine with British friends at the Praia de Luz resort in May 2007. Madeleine’s parents were named as official suspects four months after her disappearance, but Portuguese police dropped the case in July 2008 because authorities could not detect a crime. In 2013, the public prosecutor's office in Lisbon reopened the case when new leads emerged.

In June, authorities sealed off an area of scrubland near the resort in southern Portugal as part of the ongoing investigation into Madeleine’s disappearance.

The UK has a history of successfully prosecuting and in some cases jailing people for offensive online posts. Recently, Peter Nunn, 33, was jailed for 18 months Sept. 29 for online threats he made against a female member of the UK parliament.