Tony King was questioned for 10 hours by Spanish police

Tony King, 38, was arrested in connection with the murders of two teenage girls - one killed last month and one in 1999.

"We are liaising with Spanish colleagues via Interpol to establish full details of this man.

"We will then decide if any action is necessary. If Spanish police require any assistance then we will assist," Scotland Yard said.

A spokeswoman for the foreign office said Mr King had so far refused consular assistance, but they would continue to monitor the case.

Mr King, originally from Holloway, north London, has been interviewed about the murders of 17-year-old Sonia Carabantes last month and 19-year-old Rocio Wanninkhof in 1999.

He was ordered to remain in jail on Sunday by a Spanish judge while police continue investigations.

Scotland Yard said it would not comment on Mr King's past.

Outrage

Dozens of onlookers hurled abuse at Mr King as he left the Civil Guard barracks in the small town of Coin, the town where Sonia was murdered and close to his home at Alhaurin el Grande, after 10 hours of questioning by the judge.

Mr King was arrested after his girlfriend told police he had returned home on the morning Sonia disappeared, with bloody clothes and a scratched face.

The case has caused outrage in Spain

There are also reports in Spain that he has admitted raping at least three other women in southern Spain in recent years.

A second man, 36-year-old Robert Graham, is still being questioned on suspicion of helping Mr King to cover up the murders.

Sonia disappeared on 14 August while returning home from a fiesta.

Bloody clothes

Her body was found five days later strangled, beaten and stripped but there was no evidence of sexual assault.

Rocio disappeared from her home in 1999 and was found strangled and left naked. She had not been sexually assaulted.

Investigating officers said DNA samples taken from Mr King's home matched DNA recovered in the two cases.

A family friend, Dolores Vazquez, was convicted of Rocio's murder in 2001 and sentenced to 15 years imprisonment.