The South American leader was in session with international lawyers when he started playing with the device, but it suddenly emits the sound of a woman moaning with pleasure.
The footage released by LiveLeak.com reveals the s3xy sound effects caused roars of laughter in the sombre courtroom .
President Evo Morales, 57, has been in charge of Bolivia since 2006.
He is thought to be the country’s first president from the indigenous population, with previous leaders having overwhelmingly descended from European settlers.
Morales’ left-wing agenda includes tackling grinding poverty, fighting the influence of the United States and big multinational companies.
He is the head of the country’s Movement for Socialism party, but the unmarried president caused a stir by making his older sister First Lady when he was elected.
The bachelor has three children with three different mothers.
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