The family of murdered schoolgirl Alice Gross have told a coroner there is a "public interest" in knowing what checks were conducted when convicted killer Arnis Zalkalns was allowed into Britain.
The 14-year-old went missing in August last year and her body was discovered the following month in the Grand Union Canal in Ealing, west London.
Zalkalns, 41, had been named as a suspect in her disappearance but his body was later found hanging in woodland nearby. No-one else has been named as wanted in connection with Alice's death.
Police later confirmed that the builder from Latvia who had come to the UK in 2007, was responsible, and the CPS announced that he would have been charged with murder if alive.
Zalkalns had previously been convicted of murdering of his wife in Latvia and jailed for 12 years. But was he was released after serving seven and travelled to the UK.
Representing the teenager's family at a pre-inquest review at West London Coroner's Court, Rajeev Thacker asked for the scope of the investigation to be widened to look into how the killer came to be in Britain.
He said: "(For) somebody who has a criminal record, systems seemed to have been in place, we don't know exactly what they were, or what was done with them - Alice's family would like to know.
"I suspect there is a wider public interest in knowing for the future, as well."
Mr Thacker told the court, that Zalkalns's nationality was not the issue here and that Alice's family "just want answers".
Mr Thacker added: "The facts are really, Mr Zalkalns was from Latvia. Latvia is part of the EU. He was convicted of the murder of his wife and he served a prison sentence - originally 12 years, but he served seven.
"He travelled from Latvia to the UK in 2007, in 2009 he was arrested on suspicion of sexual assault."
He submitted that it would be appropriate to investigate what supervision measures Zalkalns was under after being released from prison.
Mr Thacker continued: "It is clear the police thereafter thought that he was the prime suspect. What we know is that the Home Office did check incoming passengers against a warning index since 2007 - before Mr Zalkalns came to the UK.
"The first question is was there a check of Mr Zalkalns when he came in."
"We also learned that Mr Zalkalns was arrested on suspicion of a sexual assault in 2009 and there may have been opportunity to intervene then," he added.
It was also submitted that, with regard to the Home Office's powers in relation to EU citizens, the inquest should look at what could have been done at the time, and "what happens now in terms of what lessons can be learned".
Vincent Williams, representing the Metropolitan Police, said that although the force was taking a "neutral" stance on the issues, "the police are not accepting that the police may have had some responsibility for the death".
The hearing was attended by Alice's mother, Ros Hodgkiss, her father, Jose Gross, and her sister, Nina Gross.
A full inquest into the death is due to be held at the end of November or the beginning of December, and Senior Coroner Chinyere Inyama reserved judgment on whether it would be a jury inquest.
He is expected to hand down his ruling on the scope of the inquest within 21 days.
Human rights organisation Liberty, which is representing Alice's family, has submitted that the case engages Article 2 of the European Convention on Human Rights - enshrined into UK law in the Human Rights Act.