Authorities are investigating the possible involvement of more suspects in the murder of the three surfers in Mexico, according to the Baja California state attorney general.

María Andrade said law enforcement have zeroed in on an unspecified number of alleged accomplices in connection to the killing of Australian brothers Callum Robison, 33, and Jake Robinson, 30, and their California friend Jack Carter Rhoad, 30, last week in the Pacific coast seaside town of Ensenada.

'We have more people considering that they could have participated in the investigation,' Andrade told Milenio news outlet on Monday. 'I couldn't tell you the number due to secrecy at this time.'

The attorney general's remarks were made just a day after the families identified the bodies of the surfers.