He has twice been seen with James Alexander Warke, who is on the sex offenders register held by Blackburn police.
The police, who would not release details of Warke's previous convictions, admitted they had been unaware that he was not at his home in the town.
"That is a debate we will have to have," said Detective Chief Inspector Mick Turner, who is leading the search. "It is the responsibility of police and probation officers to monitor the movements of offenders."
Unemployed Warke is well known to children, who call him Jimbo, but local people were seemingly unaware that he was on the register. He was not known to Martin's parents.
Det Chief Insp Turner said yesterday: "We now believe they have left the Lancashire area. It is possible that the two are using public transport or hitchhiking." Warke does not drive. Ports, airports, hostels and shelters nationwide have been alerted.Reuse content