SOFIA, Feb 29 (Reuters) - Bulgarian officials stepped up their bid to secure an additional fee for allowing naturalised weightlifters Boyanka Kostova and Valentin Hristov to represent Azerbaijan in the London Olympics by seeking clarification from the International Olympic Committee (IOC).
Earlier this month the Bulgarian weightlifting federation threatened to stop the two 18-year-olds from competing in London unless the payment row was resolved.
"The BOC's (Bulgarian Olympic Committee) executive board decided to turn to the IOC and the International Weightlifting Federation (to see if we have the right to demand an additional fee)," the BOC said in a statement on Wednesday.
Bulgarian weightlifting federation chief Nedelcho Kolev said the contract signed by the two countries allows Kostova and Hristov to compete at the world championships but not at the Olympics.
Last year the Bulgarian-born pair switched allegiance to Azerbaijan after the Azeri federation agreed to pay their Bulgarian counterparts a fee of 400,000 euros ($537,600).
Hristov later won a bronze medal at the worlds in Paris in November.
Azerbaijan officials said no extra payment was due.
"We agreed terms for the two lifters last year and there's no clause for additional payment," the federation said in a statement, addressed to Bulgarian media earlier this month.
The statement also said that they would consider legal action if the Balkan country blocked the duo's participation in London. (Reporting by Angel Krasimirov, editing by Pritha Sarkar)