Office of the Comptroller General of the Republic says La Linea Tunnel cost overruns can be as high as 500% according to Radio Nacional de Colombia. Comptroller says there are many white elephants like  ’for at least $ 118.00 million'. In one case a contractor was paid 90% of the station but work is abandoned.

https://www.radionacional.co/noticia/tunel-de-la-linea/sobrecostos-tunel-de-la-linea-serian-del-500-segun-la-contraloria