Lagat, the second fastest 1,500m runner of all time, is now American

Athletics Kenya chiarman Isaiah Kiplagat said that unless athletes were denied visas "we cannot stop them".

The issue is a high-profile one in Kenya, where top middle-distance runner Bernard Lagat has just announced he has became a United States citizen.

Several successful athletes have gone to compete for oil-rich Gulf states in return for lucrative packages.

Sports Minister Ochillo Ayacko said on Tuesday that his country did not allow dual citizenship and wanted defectors found training in Kenya to be deported.

But Mr Kiplagat said that like all foreigners in the country they had the right to move anywhere.

"Provided they have fulfilled all conditions we cannot stop them unless the government orders its embassies outside not to issue them with visas - but I don't think that's fair.''

Many foreign runners come to Kenya to train at high altitude, hoping to repeat the success of the country's famed runners.

Rules

On Monday, the world athletics body tightened up eligibility rules for athletes who renounce their citizenships.

Shaheen caused controversy by quitting Kenya for Qatar

Athletes who change nationality cannot now compete for their new country for three years after acquiring citizenship - although this can be reduced to 12 months if both countries involved agree.

This failed to deter Barnard Lagat, who won Olympic silver in 2004 in the 1,500m event.

"The decision to change my nationality was not one I took lightly as I am very proud of my Kenyan heritage," the 30-year-old said.

The previous most prominent example of swapping nationality is Kenyan-born 3,000m steeplechase champion Saif Saeed Shaheen.

Shaheen used to run under the name Stephen Cherono before quitting Kenya to become a citizen of Qatar.