A set of keys belonging to Brazilian woman Cecilia Haddad has been recovered from Sydney Harbour by police investigating her suspected murder.
The ABC understands a witness told police the 38-year-old's former boyfriend Mario Marcelo Santoro threw the keys from the window of a car as it travelled across Anzac Bridge.
The recovery of the keys may help police narrow the timeline surrounding Ms Haddad's death and the discovery of her body floating in the Lane Cove River.
A source has told the ABC Mr Santoro was travelling to Sydney Airport to board a flight to Rio de Janeiro when the witness saw him throw away the keys.
The ABC confirmed on Wednesday that NSW police issued a warrant for Mr Santoro's arrest several weeks ago.
Police believe Ms Haddad died in her Ryde apartment the day before a group of kayakers found her body on April 29.
Suspicions were raised immediately as Ms Haddad was found fully clothed, with weights inside each pocket of her cargo pants.
While Australia has a formal extradition treaty with Brazil, it does not apply to Brazilian citizens who are protected by local laws.
However, it is possible Mr Santoro could face legal proceedings in his home country.
That would require cooperation between the Australian and Brazilian authorities, and the sharing of evidence and information.
NSW detectives have requested Interpol issue a "red notice" similar to an international arrest warrant in case Mr Santoro leaves Brazil.
It has been revealed that Mr Santoro continued to live in Ms Haddad's apartment despite being asked to move out in the weeks leading up to her death.
Ms Haddad's family are in the process of exploring legal options to seek justice in Brazil.
