. >> reporter: chad robertson, brandon spletzer and tailor teagarden didn't responds to comments. other professionals who did responds deny the allegations. al jazeera's undercover investigation raises new questions about the possible use of performance enhancing drugs in sport. debra davis >>> a government official in southern china has killed himself a week after a devastating land slide in his city. police say he jumped from a building. he worked in the local government, the city where a pile of construction waste slid onto an industrial part burying several buildings. one person was killed and 75 are missing. the head of china telecom has become the latest high profile target of a government crackdown on corruption. the ruling communist party says he is being investigated for disciplinary violations. adrian brown reports from beijing. >> reporter: he is boss of china telecom. it is one of the three big telecommunications companies in this country. he has only been in the job since august, but according to a posting on the website of chinese anti corruption watchdog, he is now

. >> reporter: taylor teagarden, chad robertson and brandon spletzer didn't respond. other professionals named in the program who did respond denies the allegations. this raises the question of enhancing drugs used in sport >>> it is one of the most dangerous journeys in the world. the migrants journey to the united states. the best chance of getting through is by hiring a people smuggler. they must travel through in honduras, a town with the highest homicide rates in the world around get to guatemala. from there they go through another in the cartel mexican state and then people smugglers take them across the border to san antonio. we gained access to one smuggler. >> reporter: roaming one of the world's most murderous cities looking for those trying to escape. this is a people smugger in honduras. he has given us access to the clandestine business of getting people from here to the united states. a call from his latest client. >> translation: he is a migrant like any other. we're taking him to the safe house where he will stay with the others who are travelling. >>