Two European cyclists found dead in a Mexican ravine may have been murdered, investigators say, discarding their earlier claims the men had fallen while riding.

The pair – Holger Hagenbusch of Germany and Krzysztof Chmielewski from Poland – had been travelling around the world on their bikes.

They were found dead at the foot of a rock face in the southern state of Chiapas.

Investigators initially said the pair appeared to have lost control on a winding mountain road. But after it emerged that Chmielewski had suffered a gunshot wound and appeared to have had a foot chopped off, a special prosecutor was appointed to take over the case.

Luis Alberto Sanchez said: “It may have been an assault, because our investigations up to now indicate this was an intentional homicide.”

The motive appears to have been robbery, he is quoted by Agence France-Presse as saying. Belongings of both men were missing.

Mr Chmielewski’s body was found on 26 April, and Mr Hagenbusch’s further down the ravine on 4 May.

The Pole’s body was found next to the German’s bike, which initially aroused suspicion it was not an accident, the BBC reports.

Mr Sánchez said: "Those that did this wanted to make it appear like an accident, so they put the bike there, but they made a mistake and used the German's bike.”

Friends of cyclists Holger Hagenbusch and Krzysztof Chmielewski (EPA)

He added: “It was very premature to call this an accident. The bikes did not show signs of having been in a traffic accident.”

Mr Hagenbusch’s brother Rainer, who flew to Mexico to identify the body, wrote on his Facebook page that both bodies had been mutilated. “The Polish cyclist was decapitated and had a foot missing,” he said.

The Chiapas state government has now vowed to “intensify the investigation”.

Mr Chmielewski, 37, had been travelling the world by bike for three years. He had visited 51 countries was slowly making his way to South America when he was killed.

Mr Hagenbusch, 43, had been to 34 countries during a four-year ride.