The founders of the website linked to the suicide of teenager Hannah Smith said they could reveal the names of anonymous bullies to the police.
Hannah, 14, was found hanged by her 16-year-old sister last Friday at their home in Lutterworth, Leicestershire, after being abused on the social networking site Ask.fm.
Mark and Ilja Terebin, bosses of the Latvia-based website, said the site has the technology to identify "almost all users" and that they are committed to supporting the Leicestershire Police investigation.
They said "in extreme circumstances such as those we've experienced this week" they can use technology to identify those behind the taunts and "ensure this information is accessible to the appropriate legal authorities".
Meanwhile, major advertisers have withdrawn from the website, despite protests from the company that it does "not condone bullying of any kind". Specsavers, Vodafone, Laura Ashley, EDF Energy and charity Save the Children have all pulled ads from Ask.fm.
A Specsavers spokesman said the company had instructed Ask.fm to remove all of its adverts from the site due to "deep concerns over cyberbullying". EDF Energy also said it had asked its media agency to prevent any further advertising appearing on Ask.fm "with immediate effect".
Save the Children said: "We put the welfare of children first and, as a result of the tragic case of Hannah Smith, we no longer advertise on Ask.fm."
Ask.fm said in a statement that the company wanted to "reassure all users and parents of users that we are committed to ensuring that our site is a safe environment". The statement added: "We do not condone bullying of any kind, or any form of unacceptable use of our site."
Ask.fm described the teenager's death as a "true tragedy" and said they had been speaking to Leicestershire Police since the incident. They went on to say that various measures had been implemented over the past few months to continue improving users' safety, and improved reporting policies have been put in place.
David Cameron has said he was looking at what action to take "to try and stop future tragedies likes this". The Prime Minister said: "The people that operate these websites have got to step up to the plate and show some responsibility in the way that they run these websites."