The male students training to be teachers went missing in southwestern city of Iguala after they participated in a protest against discriminatory hiring and funding practices in the city. They were last seen being forced into police vans after the officers opened fire, killing six.
"There will be a new task force that will relaunch the investigation," Betanzos said at a meeting of international experts reviewing the case, as quoted by The Guardian.
The new investigation will involve satellite technology, as well as water drones in search for the bodies.
In September, an independent panel of international experts refuted the official claim that the 43 students had been burnt at a trash dump hours after they went missing.
Initially, the authorities blamed the alleged abduction on local drug cartels and criminal gangs, while additional evidence, provided by independent experts, pointed to local police and army involvement in the kidnappings.
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