KYIV (Reuters) -A young Ukrainian lawmaker involved in a probe into corruption in the defence sector fell ill and died in a taxi in Kyiv on Friday morning after what prosecutors said was a heart attack.

       Anton Poliakov, 33, belonged to the "For the Future" party, having defected from the ruling "Servant of the People" party, and sat on parliament's anti-corruption committee.

       Graft is one of Ukraine's biggest problems, and an obstacle to its bid to join the European Union and NATO.

       The General Prosecutor's Office said Poliakov had been found unconscious in the back seat of a taxi after it was stopped by a police patrol for a traffic violation.

       The driver said the passenger had got in near a public transport stop outside the city centre and then complained of feeling sick, the prosecutors' statement said.

       (Reporting by Pavel Polityuk; Editing by Kevin Liffey)