A leader of Russian-backed separatists in eastern Ukraine has reportedly been detained by fellow rebels as he returned to the Donetsk region from Russia.

A separatist official said Andrei Purgin -- who was the self-styled speaker of the self-proclaimed parliament of the Donetsk People's Republic -- was reportedly detained near the rebel-held city of Donetsk on September 4, the same day he was allegedly dismissed as head of parliament.

Ellada Shaftner, a member of the rebel parliament, was traveling with Purgin when he and his wife were detained by officials.

Shaftner said she was told by the men who stopped their car that the couple was under arrest.

A separatist official told Reuters that Purgin and his wife were being interrogated.

But Denis Pushilin, another rebel leader, denied that Purgin was under arrest.

"As far as I am informed, [Purgin] feels all right, he has not been arrested," Pushilin said on September 7.

Top rebel leader Aleksandr Zakharchenko declined to comment on the Purgin report.

Based on reporting by Reuters, TASS, and Interfax