VIENNA — Austrian prosecutors have charged three men in the slaying of a former bodyguard turned critic of Chechen President Ramzan Kadyrov, an official said Tuesday.

Umar Israilov was gunned down in broad daylight on a Vienna street in January 2009 as he was leaving a grocery store. Rights activists and Austrian investigators have linked the killing to the 27-year-old man's opposition to Kadyrov.

Michaela Schnell, a spokeswoman for the Vienna public prosecutor's office, said the men — in pretrial custody in the Austrian capital — have been charged with, among other things, accessory to murder when an attempt to kidnap Israilov went awry. A fourth man who fired the fatal shots is at large, she added.

Schnell, who declined to identify the suspects, said all face up to life in prison if convicted.

In late April, Austrian investigators concluded that Kadyrov had ordered the kidnapping of Israilov. But the Vienna public prosecutor's office said at the time that the findings were based on circumstantial evidence, including a photograph of Kadyrov and one of the accused, previously identified as Otto Kaltenbrunner, that was found on Kaltenbrunner's cell phone.

The prosecutor's office also confirmed at the time that investigators had found a connection between Kaltenbrunner and Shaa Turlayev, a close adviser to Kadyrov.

An electronic plane ticket and a copy of Turlayev's passport were found in Kaltenbrunner's car, and prosecutors also have said Turlayev had traveled to Vienna from Moscow 2 1/2 months before the killing.

Kaltenbrunner was among the men who met him at the airport, the prosecutor's office said. Another was Letscha Bogatirov, a suspect in the case who managed to flee, it said.

On Tuesday, Schnell said there was not enough evidence to charge Kadyrov.

The Berlin-based European Center for Constitutional and Human Rights said Israilov had reported that he had been repeatedly tortured by Kadyrov and had served as a chief witness in court proceedings against Russia before the European Court of Human Rights. His accounts had also formed the basis of a criminal complaint against Kadyrov on charges of torture and attempted duress filed by Austrian lawyers in June 2008.

Kadyrov has denied responsibility for Israilov's killing.

A trial date has yet to be set.