Stefano Baldini's preparations for his Olympic marathon title defence at the Beijing Games have been disrupted by the pressure on him to speak out on the Tibet issue, the Italian said.

The 36-year-old said that although he had so far kept his counsel, that should not lead people to think he did not care about last month's deadly riots in western China.

"It is a distraction," he told reporters through an interpreter. "I've had a lot of pressure to do interviews or to make statements. It becomes tiring to deal with all this stuff and I need to focus on my event.

"That does not mean we are not concerned about what is happening in Tibet," he added. "I don't like what I see in Tibet, as I don't like to see similar situations in other parts of the world."

The twice European champion was in Beijing to scout the route for what might be his final race before retirement.

Although he has not been in the best of form since he won in Athens four years ago, he thought the hot and humid conditions in Beijing in August might help him win another gold.

"The more difficult the weather conditions, the smaller the gap between the top guys and the rest," he said.

"I believe I still have a good chance of winning. It could be my last marathon... I hope to finish in the best way possible in Beijing."

Baldini said competition at the top level of men's marathon running had become much stronger over the last few years and identified Kenya's Martin Lel as the man to beat in Beijing.

Lel won his third London marathon last weekend but Baldini said the Olympic race was different from the big city marathons races and his experience of running in two previous Games would be an advantage.

An International Olympic Committee (IOC) report released earlier this year said there was a slight possibility that Beijing's pollution could cause health problems for athletes competing for more than an hour.

Ethiopian Haile Gebrselassie, an asthmatic, has decided not to run the 42-km endurance race in Beijing.

Although his coach was complaining of a sore throat after two days in the city, Baldini said he was confident the efforts the authorities were making to improve air quality would work.

"The pollution is a problem only for people who have medical problems like Haile," he said.

"For me it is not a problem... we are right to worry about it because it is serious but I think it will better in August."

Baldini said despite all the current problems attached to the Beijing Games, he thought come August there would be as good an atmosphere as there was at all Olympics.

"My real hope is that when the Olympics come we can talk about sport," he said.