A serial paedophile linked to the Madeleine McCann case was yesterday jailed for life for murder.
Charles O'Neill has repeatedly refused to be quizzed by detectives working for Maddie's parents Kate and Gerry.

But the private eyes will now try again. O'Neill, 47, is believed to have been in Portugal when Maddie, then three, vanished from an apartment in Praia da Luz on the Algarve in May 2007.

Yesterday he was sentenced for killing mum-of-three Allison McGarrigle who threatened to reveal he and gay lover William Lauchlan were abusing a child.

Ex-boxer O'Neill and Lauchlan, 33, strangled Allison 13 years ago in Largs, Ayrshire.

They dumped her body at sea and it has never been found.

The High Court in Glasgow ordered O'Neill to serve a minimum of 30 years and Lauchlan, a minimum of 26 years.

They were handed a further 10 years each for abusing two boys aged six and 14.

The pair had been jailed in 1988 over 31 charges of drugging and assaulting young children but were freed in 2002.

They fled to Spain and set up a cleaning business for holiday apartments.

They travelled to Portugal several times.

In April 2004 they abducted, drugged and abused a 15-year-old English boy in Spain.

O'Neill was still there three years later when seven-year-old Spanish Jeremy Vargus vanished from Gran Canaria.

Two months later Maddie went missing - and O'Neill was thought to be on the Algarve at the time.

Jeremy's mother Ithaisa Suarez, 24, and Kate, 41, from Rothley, Leics, have written to each other regularly.

Kate and Gerry have also included information about the Jeremy case on their website.

Last night the McCanns' spokesman Clarence Mitchell confirmed "Investigators have been fully aware of O'Neill and his background but have not been able to take him any further forward as an active line of investigation."