Mami Konneh Lahun, 24, last seen after finishing the 26.2 mile race in 20th place, was due to return home today, but failed to show up for her flight home.
The London Metropolitan Police put out an appeal when the runner failed to return to her temporary accommodation in Greenwich yesterday.
Although athletes are normally allowed into Britain to compete on a temporary visa, this would not be the first time that a competitor from a third world country has refused to return home and subsequently lodged claim for asylum in the UK.
Whatever the grounds for a asylum, the days when it would be relatively easy to arrive in the UK on a visitor visa, claim asylum and then stay here for years until the Home Office got around to looking at their case, and if refused (as most are) lodge a series of appeals funded by legal aid, are long gone.
The Home Office now 'fast track' claims within months, however, thousands of people have been granted a type of amnesty under the 'legacy' (or lost) cases, some of which had been hanging around for 10 years or more.
The 14 year 'long stay concession' no longer exists, which means an illegal immigrant or visa overstayer must wait 20 years before applying indefinite leave to remain (UK residency).
Migrants who manage to remain in the UK legally for 10 years, for instance on a student visa, can still apply for residency.
If you are considering coming to the UK, you can still look at Tier 2 work permit routes, Tier 1 highly skilled and entrepreneur visa or under a Tier 4 student visa.
Those with relatives who are UK residents or EEA nationals may have other options under family migration routes.
With a wide range of migration routes to the UK, it seems strange that many migrants still seek 'back doors' methods or pay thousands of pounds to traffickers to transport them halfway across the world on the back of a lorry.
If you need advice on any immigration matter, EU or UK immigration law, or want to appeal against a refusal, call Cynthia Barker on 020 8731 5972 or email her your details to firstname.lastname@example.org. Cynthia Barker is an OISC registered Immigration Adviser with a team of Level 3 Immigration Law Practitioners, Concept Care Solutions, Middlesex House, 29-45 High Street, Edgware, HA8 7UU.